English for Academic Skills
Independence
[EASI]
Session 7
Vocabulary
By the end of this session you will be able to ……
• identify common prefixes
What is a root word?
A word (or part of a word) which can make other words
when letters are added to the beginning or end.
What are the roots of these words?
microscope
thermometer
photograph
What is a root word?
What are the roots of these words?
microscope
micro = small
scope= viewing instrument
thermometer
thermo = heat
meter = measuring instrument
photograph
photo = light
graph = writing
What is an affix?
A letter, or letters we can add to a root word to change
either its meaning or its function.
Affixes can be divided into two types:
• Prefixes – added to the start of a word
– anti, un, dis, re, pre, e
• Suffixes – added to the end of a word
– -tion, able, ly
noun, verb
interest
prefixes
adjective
adjective
adverb
adjective
adjective
noun
adjective
affixes
suffixes
interesting
uninteresting
interestingly
interested
uninterested
dis interest
dis interested
Facebook is interesting.
Facebook is uninteresting.
Interestingly, he logged out of Facebook.
I am interested in Facebook.
I am uninterested in Facebook.
He showed disinterest toward Facebook.
A good jury should be disinterested.
What is a stem word?
A word which can stand on its own when the affix(es)
have been removed.
For example:
interest
We can’t take away any parts of this word. For example:
terest
inter
(not a word)
(a different meaning)
Where is the stem of this word?
interaction
action
act
misrepresentation
representation
represent
present
Prefixes
Adding a prefix to a word changes its meaning.
Some common prefixes:
prefix
meaning
example
dis
opposite / reverse
disagree
il, im, in, ir
not
inactive, impossible
re
again
restate
un
not
uncertain
More prefixes
For each prefix, decide the meaning and think of
examples:
prefix
meaning
example
anti
against
antisocial
de
opposite
deregulate
inter
between
international
mid
middle
midyear
mis
wrongly
misguide
non
not
nonessential
over
over
overexcited
pre
before
preview
semi
half
semiconscious
under
under
understate
Hyphens and prefixes
Which of the following is right?
co-operate
cooperate
Both are acceptable.
Rule of thumb
• use a hyphen if the prefix ends with a vowel (a, e, i, o, u) and
the stem word begins with a vowel:
re-organise
Hyphens and prefixes
Hyphen or no hyphen?
preapprove
pre-approve also ok
preeminent
pre-eminent also ok
reorganise
re-organise also ok
reenrol
re-enrol also ok
antiinflammatory
anti-inflammatory
Hyphens and prefixes
Sometimes a hyphen is necessary. What is the
difference here in:
1) pronunciation
2) meaning
/rɪˈzent/
I resent the email.
/ri:ˈsent/
(I’m not happy about what it says)
I re-sent the email. (I sent it again)
Commonly confused prefixes
- inter / intra
Human
resources
- An interdepartmental meeting.
- between different departments
Sales
- An intradepartmental meeting.
- within one department
What is the difference?
Administration
Sales Manager
Administrator
Salesperson
Salesperson
Salesperson
Commonly confused prefixes
- hypo / hyper
- Is this a:
- hyperdermic needle
- hypodermic needle
- A person might suffer from:
- hypertension - high blood pressure
- hypotension - low blood pressure
hyper = over / too much
hyperactive
(too active)
hypo = under
hypodermic
(under the skin)
More commonly confused / confusing prefixes
ante anti
before / in front of
Parents can attend antenatal classes.
against
We should all be anti-war.
bi di
two (Latin)
biannual, bilateral, bisexual
dia
across / through
The Earth is 12,742 km in diameter.
two (Greek) (Chemistry)
carbon dioxide, disulphuric acid
di
two (Greek) (Chemistry)
carbon dioxide, disulphuric acid
dis dys
reverse (Latin)
disconnect, dislike, disambiguate
(medical)
bad / abnormal (Greek)
dyslexia, dystopia, dystrophy
hyper
over / too much
hyperactive, hypercritic, hypermarket
inter
between
international, interpersonal, internet
pre
before
precede, predate, prepay
hypo
under
hypodermic needle, hypoallergenic
intra
within
intravenous, intrapersonal, intranet
pro
in favour of / forward
proceed, propel, propose
super supra
directly on top of
superimpose, supersize, supervise
above
supraliminal, supranational suprarenal
Some fun with prefixes…
Some words are not complete without their prefixes,
but sound like they should be.
For example:
dissertation
long, well
researchedwriting
writingofofpoor
high
a short,
unresearched
quality – often at the end of a degree
Unsurprisingly, he got a ‘D’ for his sertation.
delicious
not
all
verytasty
tastyat(food)
Don’t eat at that restaurant, the food is licious.
Visit this page for more fun: http://public.wsu.edu/~busselle/Wordfunwb.htm
Some fun with prefixes…
Some words are not complete without their prefixes,
but sound like they should be.
For example:
dissertation
These are not words!
delicious
Visit this page for more fun:
http://public.wsu.edu/~busselle/Wordfunwb.htm
Homework
Good sources of information and practice:
http://www.englishclub.com/vocabulary/prefixes.htm
http://www.englishgrammar.at/online_exercises/prefixes-suffixes/prefixessuffixes-index.htm