Did you have trouble ________ the post office?

be-subjunctive

collective nouns

determiners

antecedent

What is given information and what is new information?

Explain the relationship between tense and time.

Using inversion:

I have never been there before.

Using a YES-NO question:

I have already finished the assignment the teacher gave us last week.

Reinforcing the negation:

These goods are not satisfactory.

Using a non-finite form.:

Don't take his words seriously if he professes that he knows everything about your history.