English grammar is a popular item on most standardized tests including many ESLEFL tests.  Below are English grammar practice test questions.
Here are a few sources for English Grammar – Wikipedia,     The English Club.

1.  Choose the sentence with the correct grammar.

a)  He would have postponed the camping trip, if he would have known about the forecast.
b)  If he would have known about the forecast, he would have postponed the camping trip.
c)  If he have known about the forecast, he would have postponed the camping trip.
d)  If he had known about the forecast, he would have postponed the camping trip.

2. Choose the sentence with the correct grammar.

a)  If Joe had told me the truth, I wouldn’t have been so angry.
b) If Joe would have told me the truth, I wouldn’t have been so angry.
c)  I wouldn’t have been so angry if Joe would have told the truth.
d)  If Joe would have telled  me the truth, I wouldn’t have been so angry.

3. Choose the sentence with the correct grammar.

a)  He doesn’t have any money to buy clothes and neither do I.
b)  He doesn’t have any money to buy clothes and neither does I.
c)  He don’t have any money to buy clothes and neither do I.
d)  He don’t have any money to buy clothes and neither does I.

4. Choose the sentence with the correct grammar.

a)  Because it really don’t matter, I don’t care if I go there.
b)   Because it really doesn’t matter, I doesn’t care if I go there.
c)   Because it really doesn’t matter, I don’t care if I go there.
d)   Because it really don’t matter, I don’t care if I go there.

5. Choose the sentence with the correct grammar.

a)  When we go to the picnic, we will take potato salad and wieners.
b)  If you come to the picnic, bring potato salad and wieners.
c)  When we go to the picnic, we will bring potato salad and wieners.
d)  If you come to the picnic, take potato salad and wieners.

6. Choose the sentence with the correct grammar.

a)  Until you take the overdue books to the library, you can’t take any new ones home
b)  Until you take the overdue books to the library, you can’t bring any new ones home.
c)  Until you bring the overdue books to the library, you can’t take any new ones home.
d)  Until you take the overdue books to the library, you can’t take any new ones home.

7.  Choose the sentence with the correct grammar.

a)  Newer cars use fewer gasoline, and produce fewer emissions.
b)  Newer cars use less gasoline, and produce less emissions.
c)  Newer cars use less gasoline, and produce fewer emissions.
d)  Newer cars fewer less gasoline, and produce less emissions.

8. Choose the sentence with the correct grammar.

a)  His doctor suggested that he eat less snacks and do fewer lounging on the couch.
b)  His doctor suggested that he eat fewer snacks and do less lounging on the couch.
c)  His doctor suggested that he eat less snacks and do less lounging on the couch.
d)  His doctor suggested that he eat fewer snacks and do fewer lounging on the couch.

9. Choose the sentence with the correct grammar.

a)  However, I believe that he didn’t really try that hard.
b)  However I believe that he didn’t really try that hard.
c)  However; I believe that he didn’t really try that hard.
d)  However: I believe that he didn’t really try that hard.

10. Choose the sentence with the correct grammar.

a)  There was however, very little difference between the two.
b)  There was, however very little difference between the two.
c)  There was; however, very little difference between the two.
d)  There was, however, very little difference between the two.

1. D
The third conditional is used for talking about an unreal situation (a situation that did not happen) in the past.  For example, “If I had studied harder, [if clause] I would have passed the exam [main clause].  This has the same meaning as, “I failed the exam because I didn’t study hard enough.”

2. A
The third conditional is used for talking about an unreal situation (a situation that did not happen) in the past.  For example, “If I had studied harder, [if clause] I would have passed the exam [main clause].  This has the same meaning as, “I failed the exam because I didn’t study hard enough.”

3. A
Shows agreement with a negative statement by using “neither.”

4. C
Doesn’t, does not, or does is used with the third person singular–the pronouns he, she, and it. Don’t, do not, or do is used with first, second, and third person plural.

5. A
Whether to use “bring” or “take” depends on location. Something coming toward the subject’s location is brought. Something going away from the subject’s location is taken.

6. C
Whether to use “bring” or “take” depends on location. Something coming toward the subject’s location is brought. Something going away from the subject’s location is taken.

7. C
“Fewer” is used with countable nouns and “less” is used with uncountable nouns.

8. B
“Fewer” is used with countable nouns and “less” is used with uncountable nouns.

9. A
“However” is bracketed with a comma after it at the beginning of a sentence.

10. D
“However” is bracketed with a comma before and after it within a sentence.