Theories of
Second Language Acquisition
(SLA)
Created by Dr. Keya Mukherjee. Revised by Dr. Jeffra Flaitz
Opinions about Language Learning
• Languages are learned mainly through imitation.
• People with high IQs are good language learners.
• Most of the mistakes ELLs make are due to interference
from their native language.
• Errors should be corrected as soon as they are made in
order to prevent the formation of bad habits.
Second Language Acquisition
• What does it mean to know a language?
• What does it mean to know a second language?
• How are second languages learned? In what order?
What helps, what doesn't help?
SLA is concerned with how people
learn a second language
and with how to provide teachers with a
psycholinguistic basis for teaching ELLs.
FIRST Language Acquisition
• What do you know about how children learn their first
(i.e. native) language?
• What are the stages of first language acquisition ?
• What is a child doing in each of these stages?
What we now know from research
on children’s language development
• Humans are born with Language Acquisition Device,
a system that allows us to learn language
• Children go through different language learning stages
– babble at 6 mo
– 1-word utterances at 1 yr
– 2 word utterances at 1.5 yrs
– word inflections at 3yrs
– complex constructions around 5 years
– mature speech around 10 yrs
What we now know from research
on children’s language development
• There is a Critical Period during language learning
must occur. In other words, there is a correlation
between age and eventual success at attainment of
language.
• Language ability does not seem to be correlated with
intelligence.
Review of Kinds of Linguistic Knowledge
• Phonology: knowing the sounds of the language
• Morphology: knowing how to form words
• Lexicon: the mental dictionary of words
• Syntax: knowing about acceptable sentences
• Semantics: knowing word meanings
• Pragmatics: knowing how to use language in social context
• COMPETENCE: knowledge about language rules
• PERFORMANCE: ability to use language to communicate
How do we learn our native language?
• Our biological and innate cognitive ability, that which
Noam Chomsky called Language Acquisition Device
(LAD), means that humans are specially wired for
language, which is our unique human capability.
• Native language competence develops from exposure to
language. Children “pick up” the language spoken in
their environment.
• We are able to formulate the rules of a language without
being explicitly taught.
Look at the following language sample
1. A speaker says: “I eated chicken yesterday.”
Who is likely to make this utterance?
• A child learning their L1 (native language)? 
• A beginning learner of an L2 (second language)? 
• An L2 speaker for 35 years? 
2. The same speaker says: “I ate chicken yesterday.”
– The past tense verb now looks like standard English.
3. Hold on! Now the same speaker says:
“I goed to visit grandma yesterday.”
-- Given this lack of consistency, what can you say about
the speaker’s acquisition of the past tense?
Look at the following language sample
3. Hold on! Now the same speaker says:
“I goed to visit grandma yesterday.”
-- Given this lack of consistency, what can you say about
the speaker’s acquisition of the past tense?
Those who understand the process of language
acquisition recognize that the speaker has learned that
most past tense verbs end in –ed (e.g. waited).
The speaker also seems to understand that some past
tense verbs in English are irregular (e.g. ate).
It appears, however, that the speaker hasn’t yet figured
out which verbs have irregular past tense forms.
Why is acquisition represented
as a U-shape?
ate
eated
ate
ated
Why study these developmental patterns?
• These developmental patterns are part of what is called
INTERLANGUAGE
• Interlanguage data reveal the different stages of acquisition
• Interlanguage describes a learner’s language in its own right
Why Study about SLA?
Linguistics:
• Suggests that SLA is a component of the broader study
of language, a unique human faculty
Language Pedagogy
• Designing effective teaching methodologies, assessing
reasonable expectations
Language Policy
• Bilingual education, language laws
Does SLA mimic
First Language Acquisition?
YES
and
No
They are more similar than dissimilar.
Findings in L1 vs. L2 Acquisition
L1 Acquisition development studies
Brown (1973) and de Villiers and de Villiers (1973)
found clear orders and sequences in the acquisition of
grammatical morphemes by first language learners.
L2 Acquisition development studies
Dulay and Burt (1973), Bailey, Madden, & Krashen
(1974), Larsen-Freeman (1976), and Pica (1983) also
found clear orders and sequences in the acquisition of
grammatical morphemes by second language learners.
Findings in L1 vs. L2 Acquisition
• Research has demonstrated that children from
different language backgrounds (e.g. Spanish or
Chinese) learning English as a second language
showed similar order of acquisition of word
inflections as the order of acquisition manifested by
their L1 peers.
• HOWEVER, this finding could not be generalized to
adult L2 acquisition of English. In other words, the
developmental patterns of SLA among child-aged
ELLs is different from those observed in adult-aged
ELLs.
Findings in L1 vs. L2 Acquisition
• The NATIVE language has less of an impact on the
order of acquisition than the nature of the TARGET
language.
• The natural order CANNOT be changed through
instruction.
• If you know the grammatical rule you MAY NOT be able
to apply it.
Early L2 development is generally
characterized by …
• Silent period:
a period of time when the learner does not say anything
and understands little
• Formulaic speech:
speech is structured, learner produces formula-like
utterance (e.g. That’s a …, I want …)
• Structural and semantic simplification:
learner produces very simple sentences
These patterns are similar to that of L1 acquisition
Differences
between L1 and L2 Acquisition
• External factors:
social situation in which learning took place, input and
interaction
• Internal factors:
age, motivation, style, strategies, language transfer
L1 vs. L2 Acquisition Circumstances
FIRST LANGUAGE (L1)
SECOND LANGUAGE (L2)
Learned at home
Learned at school, work
Learned by infants and toddlers
All ages, oftentimes older
Learned in order to communicate
with loved ones
Learned to communicate with loved
ones, community, co-workers, or to
succeed in US job market
Largely and unconscious process
Very conscious process, structured,
learned not acquired, stressful,
ongoing, use it or lose it, never
becomes your L1
Not time pressure to learn
Pressure of a timeframe, social and
academic
Must learn developmental concepts
as well as language
Transfer developmental concepts to
L2 for older learners
Some conclusions we can draw
There are many unanswered questions with regard to the
similarities and differences between learning a second
language and learning one’s first language.
The bottom line seems to be that SLA progresses in a
systematic order that is similar to but not completely
identical to the orders observed in first language
acquisition.
Pause and Think…
The following is a sample of speech from an ELL whose
native language is Spanish.
What observations can you make about this ELL’s
interlanguage (silent, formulaic, L1 transfer, mistakes)?
1.
2.
3.
4.
5.
6.
7.
Lookit, like that.
Lookit four cars. Hey look, dese.
Looky chicken.
Look two cars
Lookit gas.
Lookit four.
Hey look, lunch money.
Stages of Language Acquisition
• Pre-production (Level 1)
“Silent Period”, 500 word receptive vocabulary
• Early production (Level 2)
Limited comprehension, one or two-word responses, 1000
word receptive vocabulary
• Speech Emergence (Level 3)
Good comprehension, errors in grammar, simple sentences,
3000 word receptive vocab.
• Intermediate Fluency (Level 4)
Excellent comprehension, complex and varied sentence
structure, 3000+ words
What attempts have been made in the past
to explain how humans learn a language?
A few prominent theories were espoused to explain the
process of language acquisition. They came from:
B.F. Skinner: The Behaviorist Model
Noam Chomsky: The Innatist Model
Lev Vygotsky: The Interactionist Model
(or Socio-cultural Theory)
Historical Perspective
Recent History on SLA Research
B.F. Skinner’s Behaviorism
In the 1950’s and 1960’s, the techniques of language
teaching were based on a behaviorist view of
language.
Language under this view is essentially a system of
habits; learning proceeds by producing a response to
a stimulus and receiving either positive or negative
reinforcement.
Behaviorist Theory
A psychologist by training, a Harvard researcher, and the
chief proponent for the behaviorist model of learning,
Skinner believed that …
• language learning is not a unique process. All humans
go through the same stages of language acquisition
(cooing, babbling, one-word utterances etc).
• language learning is habit formation and is shaped by
conditioned behavior. Learning will take place based on
the reinforcement received for the response.
• there is no concern for the existence of any
“underlying mental processes.”
• a learner’s mind, according to Skinner, is a blank slate.
Behaviorism and Language Learning
• Based on this view, language teaching was seen to
involve a lot of pattern repetitions to instill proper
habits in the learner.
• For L2 learners, there was also the matter of
“unlearning” certain interfering habits from the L1.
Problems with Behaviorist Thinking
• Language isn’t a collection of habits (Chomsky).
• L1 acquisition shows that …
– children do not merely repeat what they have heard;
they use language creatively.
– children internalize rules by producing sentences
during the different stages of language acquisition.
Innatist Theory
A linguist by training, MIT researcher, and chief proponent of
the Innatist Theory of language acquisition, Chomsky
believed that …
• language learning is an innate biological ability in all
humans; we have a predisposition to language learning
thanks to our “language acquisition device” or LAD.
• Language is learned through a complex process of rule
generation, hypothesis testing and confirmation.
• Our ability to create infinite sentences from a finite set of
rules is given as primary evidence of the LAD.
• Learners play an active role in their language
development, even if the role seems effortless and
“un”conscious.
Interaction (Socio-cultural) Theory
Born in post-Czar Marxist Russia, Vygotsky was both a
psychologist and linguist by training and believed that …
• human cognitive development, including language
development, is a result of social interaction; it is
specifically related to the individual’s culture and is
aimed at creating a shared knowledge of the culture.
• Adult scaffolding of knowledge through speech helps the
child internalize both language and cultural knowledge.
• Social interaction during scaffolding helps the learner with
full development in their zone of proximal development
(ZPD).
• Although children use language to learn and think, its
main purpose to them is social interaction.
How did these learning theories
influence SLA theories and approaches?
1.
Behaviorist Theory gave birth to approaches such as the
Audiolingual Method (drill and practice)
2.
Innatist Theory gave rise to Krashen’s Monitor Model
(5 hypotheses)
3.
Interactionist (Socio-cultural) Theory resulted in greater
emphasis on the “tools of thinking,” practices such as
cooperative learning, reciprocal teaching, and
scaffolding, and consideration of the learner’s social
and cultural experience.
Behaviorism
Contrastive Analysis
• Contrastive Analysis (CA) focused on comparing and
contrasting languages to find areas of difference.
• Learner errors were accounted for by looking at the
differences between languages.
• Differences were to be brought to the attention of the
learner; similarities were to be subconsciously
transferred from the L1.
• Source of difficulty in learning an L2 was believed to be
determined by the differences between the L1 and the L2.
Problems with using the CA approach
• In language learning, L2 learners use many of the same
cognitive strategies as L1 learners do.
• Many errors that L2 learners make cannot be traced to
the influence of their L1.
• “Transfer of habits” is not consistently found to be the
source of learner errors.
• CA cannot explain why a learner could easily produce an
erroneous form, struggle with the form, and then
produce a correct form.
• The task of enumerating the “differences” between
languages is not straightforward; hence it is hard to
predict where the problems would arise.
Error Analysis:
One of next steps in language pedagogy
• Ultimately, looking at the differences between languages
was not a viable approach for articulating language
teaching pedagogy. Thus, the next step was to look at
learner errors as opposed to mistakes.
• Error  Mistake
• Mistake: a random performance slip caused by fatigue,
excitement, etc. It can be easily corrected.
• Error: a systematic deviation from the rules made by
learners who have not yet mastered the L2. Errors cannot
be self-corrected. They reveal the learner’s underlying
competence or hypotheses about rules.
• The expectation is that learning the source of the error,
would reveal more about interference and developmental
patterns.
Error Analysis
• Analyzing L2 learner errors showed that the majority
of the them were not the result of L1 interference,
but they were rather “internal” errors of the
“interlanguage” of the learner.
• Error Analysis (EA) showed that L2 learners have a
grammatical system, “interlanguage”, which falls on a
point along a continuum somewhere between zero
proficiency and perfect proficiency.
• This is a developing system and hence the question
of stages of development is raised.
Problems with Error Analysis
Despite the popularity of error analysis as an approach to
investigate and understand second language learning …
• sole focus on learners’ errors denied access to the whole
picture
• many of the sources of learners’ errors could not be
identified
• the EA hypothesis could not account for all the areas in
which the learner was having difficulty (e.g. avoiding
certain structures)
Interlanguage (IL):
another look at learners’ interim language
• A learner’s interlanguage is the intermediate status of
the learner’s system between the L1 and the L2
• Interlanguage data shows evidence that the process of L2
development is systematic and rule governed
• Evidence of systematic stages of IL development is seen
in the acquisition of interrogatives, negation, word
order, and other aspects of syntax.
Interlanguage Development
Stages of Negation
Stage 1: No + X
ex: no book; no is happy; no you pay it
Stage 2: No/Don’t + verb
ex: I don’t like LA; I don’t swim; I don’t can play good;
He don’t like job.
Stage 3: Auxiliary + negation
ex: I can’t play; It wasn’t big
Stage 4: Unanalyzed “don’t” and auxiliary + negative
ex: I don’t like apples; I can’t play; She doesn’t drink
alcohol; They weren’t at home
Interlanguage Development
Acquisition of Questions
Stage 1: WH + declarative order
ex: What you want, what you eat, where we go
Stage 2: Stage 1 utterances continue; “be” is inverted;
few examples of other verb inversions
ex: where is mine’s, where is John’s, what say they
Stage 3: “Be” is correctly used; auxiliary “do” emerges
in WH questions; “do” also appears correctly in “Y/N”
answers; double marking of tenses
ex: where did he found it; where’s this one belongs
Interlanguage Activity #1
What can you conclude about the interlanguage of the ELL
(native language is Spanish) whose data is shown below?
In particular, how does this speaker produce English
negatives? At which stage (of negation acquisition) is the
learner? How did you arrive at this conclusion?
1. No write.
2. No like it.
3. I no like American food.
4. No money.
5. My brother no go to school yet.
6. This may be no good for you.
7. I don’t know English.
8. No in house now.
9. I don’t know word.
Interlanguage Activity #2
Examine the following sample of spontaneous speech by
a Japanese child, age 5-6 years old. What observations
can you make about his development of question
formation in English?
Month 1
Month 2
Do you know?
How do you do it?
Do you have milk?
Do you want this one?
What do you doing, this boy?
What do you do it, this froggie?
What do you doing?
What do want it?
Implications of Error Analysis for Teachers
•
•
•
•
Look at learners’ errors carefully
Don’t be misled by constructions in stage 2
Pay attention to fossilization (pause in learning)
Work with students’ errors
– Discuss, analyze, categorize
– Don’t overcorrect
– Encourage “self-correction”
– Be sensitive – don’t embarrass
– Model correct answers
– Don’t ignore errors
– Motivate and encourage success
– Create an atmosphere that will encourage
students to produce in the L2.
Stephen Krashen’s Monitor Model
A linguist from the MIT tradition, Krashen’s theory of SLA,
popularly known as the Monitor Model, is based on the
following 5 premises:
1. Language acquisition and language learning are two
distinctively different processes.
2. In SLA, as with first language acquisition, there is a
natural order in the acquisition of grammatical
morphemes; however, the order does not need to be the
basis of language instruction.
3. In order for SLA to take place, the input the learner
receives must be made comprehensible through the use
of communicative methodology.
http://www.sdkrashen.com/
Stephen Krashen’s Monitor Model
4. Along with comprehensibility, when the input is slightly
above the current level of the learner’s competence,
then the learner’s is more likely to learn in this Zone of
Proximal Development.
5. Learners also use a conscious system of rules, also
known as the monitor to guide their language learning
and production; however, use of the monitor depends on
the amount of time available, the amount of knowledge
amassed, and the learner’s desire to use the rules.
http://www.sdkrashen.com/
Krashen’s 5 Hypotheses
1. The Acquisition-Learning Hypothesis
2. The Monitor Hypothesis
3. The Natural Order Hypothesis
4. The Input Hypothesis
5. The Affective Filter Hypothesis
Krashen's Five Hypotheses
Hypothesis 1:
Acquisition versus learning refers to language acquisition as
the subconscious internalizing of implicit rules, whereas
learning refers to the conscious process that results in
knowing about the language
Hypothesis 2:
Our brains “monitor” our use of rules during language
production. An overactive monitor inhibits language
production whereas an underactive monitor causes the
learner to produce language in an haphazard way. The
monitor can only be optimally used when the learner has
time and is conscious of the rules.
Krashen's Five Hypotheses
Hypothesis 3:
Grammatical morphemes are acquired in a fixed order;
hence, explicitly teaching grammar has little impact.
Learners will acquire the forms when they are “psycholinguistically ready.”
Hypothesis 4:
Provision of comprehensible input speeds up language
learning.
Hypothesis 5:
The learner’s “affect” (feelings) can interfere with effective
language learning; hence, s/he needs to be made to feel
comfortable and confident.
Highlights from Krashen's Monitor Model
The Role of Input:
• Must be modified and adjusted
• Must use “foreigner talk” (slowed down, simplified)
• Must be comprehensible
• Must be one step beyond current competence (i+1)
Acquisition Rich Environment
• Meaningful interaction rather than drills
• Exposure rather than instruction
• Communicative tasks
• Negotiation of meaning
Implications of Interactionist
(Socio-cultural) Theory for Teaching
Research Findings
• Classroom interaction and opportunities for participation
with peers give learners a chance to evolve and enjoy
social as well as learning success.
• Peer groups and collaborative learning play a very
important role in facilitating cultural learning, competent
pragmatic use of language, as well as constructing
knowledge.
• Guidance and collaboration allow the learner to grow
within his/her Zone of Proximal Development.
http://www.stemnet.nf.ca/~achafe/cooplang.html
Research Findings
• Learners benefit from extrinsic learning rewards as well as
from the intrinsic reward of having learned something.
• Second language learners benefit from integrating into the
school community as well as the larger social context.
• There is a positive impact on the process of second
language learning when …
• the learning context is enriched through opportunities to
learn both language and culture via social interaction
• the students’ worldview and background are positively
exploited for the benefit of others
• the student’s culture is validated and acknowledged.
http://www.cal.org/resources/digest/digest_pdfs/0005-contextual-walqui.pdf
Other Findings from SLA Research
• Interaction and instruction have positive effects on second
language learning (rate, ultimate level of attainment)
– Michael Long
• Awareness of language learning strategies helps the
learner learn the second language – Rebecca Oxford
• There are two levels of language that must be acquired:
Basic Interpersonal Communication Skills (BICS) and
Cognitive Academic Language Proficiency (CALP)
–
Jim Cummins
• Students must receive explicit language instruction
• Learner differences account for differences in second
language learning
Summary of Language Acquisition
• The child learns language by unconsciously generating
rules, perhaps to fill and innate blueprint (Chomsky).
• Errors often indicate that learning is taking place.
• The child learns language in meaningful, supportive, and
communicative settings.
• The child understands more than he can say.
• The child will require a lot of time to become fluent.
Name That Hypothesis
All children with normal hearing and articulatory
mechanisms acquire their first language
Hypothesis:
By whom?
Name That Hypothesis
Attempting to communicate enables acquisition.
Learners learn by doing.
Learners need to be pushed to go beyond what they can
currently do.
Hypothesis:
By whom?
Opinions about Language Learning
REVIEW
Languages are learned mainly through imitation
• False
• If it were true, how can the following utterance be
explained? “I goed to school”
People with high IQs are good language learners.
• True: They are good at learning about the language
• False: They are not good at acquiring the language
for communicative purposes.
Opinions about Language Learning
REVIEW
Most of the mistakes made by second language learners
are due to interference from their first (native0 language.
• True: for pronunciation and some other features
(false friends, word order)
• False: Speakers of a variety of different native
languages make many of the same errors.
Opinions about Language Learning
REVIEW
• Errors should be corrected as soon as they are made in order
to prevent the formation of bad habits.
• False: Can negatively affect self-esteem and motivation
• False: Impossible to correct every single mistake
• False: Errors are a natural part of language development
• False: Errors help students “to notice the gap” between
their current understanding and where they need to make
adjustments