No Article
When a plural or non-count noun is indefinite, an article is not required


Cities are often crowded.
Money is hard to get and hard to keep.
Indefinite means that the noun does not refer to any specific thing.
SUBJECT-VERB AGREEMENT
The main verb must agree with the subject of the sentence or clause. If the subject is singular, the verb
must be singular. If the subject is plural, the verb must be plural.
Some nouns look plural but are actually singular.



Nouns that end with -ics are often singular, especially when they refer to a field of study
(physics, economics, mathematics).
The names of diseases are singular (measles, rickets).
The noun news is singular.
The names of companies are singular, even if they include plural words.

National Tires has increased its prices.
Sums of money take singular verbs.

Five hundred dollars is a lot to pay for a hotel room. (singular subject, singular verb)
Words that begin with every and no (everybody, everything, nobody, nothing) take singular verbs.
CONDITIONAL SENTENCE
A conditional sentence describes an action or situation that is necessary (the condition) in order for
another action or situation to occur (the result).
A conditional sentence is made up of two clauses-an if clause, or condition, and a main clause, or result.
A conditional can be either real or unreal
REAL FUTURE CONDITIONALS
Real conditionals are about things that are really true or that can really happen. Real future conditionals
are about things that can really happen in the future.
In a real future conditional sentence


The verb in the main clause is in the future tense.
The verb in the if clause is in the present tense.
Sam will have a lot of expenses if he buys a new house.
The sentence above is a real future conditional. It is really possible that Sam will buy a new house in the
future. If he does, the result will be that he will have a lot of expenses.
If Sam doesn't get the job, he won't buy a new house.
The sentence above is also a real future conditional. It is really possible that Sam won't get the job. If he
doesn't get the job, the result will be that he won't buy a house
UNREAL PRESENT & PAST CONDITIONALS
Unreal conditionals are about things that aren't real or can't really happen.
A present unreal conditional is about something that is not true in the present, but can be true in future


The verb in the if clause is in the past tense.
The verb in the main clause uses would+ base form.
If Mary had a better job, she would earn more money.
The sentence above is a present unreal conditional. The truth is that Mary doesn't have a better job and
she doesn't earn more money.
In a present unreal conditional sentence, the correct form of the verb be is always were, no matter what
the subject is.
If Mary were rich, she would buy many things.
A past unreal conditional is about something that wasn't true in the past.
• The verb in the if clause is in the past perfect tense.
• The verb in the main clause uses would+ have+ past participle.
If Mary had gotten up early this morning, she would have gotten here on time.
The sentence above is a past unreal conditional. The truth is that Mary didn't get up early this morning
and didn't get here on time.