On the question of English sentence structure, English learners help! !

1. The answer to your first question is yes. For example, if he comes here tomorrow, tell him to call me back. If he comes tomorrow, tell him to call me back. If here leads to the conditional adverbial clause. But I can't understand that sentence in the book you gave me because it doesn't make sense in theory. Did you make a clerical error when typing, or did you not write it all?

2。 A complex sentence consists of a main clause and one or more clauses. Imperative sentence plus clause is originally a kind of master-slave complex sentence. Subject-predicate complex sentences do not require the subject of the subject and clause to be the same. For example:

Do you know whether he is a scientist?

I was watching TV when my mother came back.

Master-slave protocol refers to. However, not all subject-subject complex sentences must be consistent in tense, which involves too many exceptions. You can check the grammar book for details. But as far as you are concerned, if the main clause is imperative, then the clause usually uses the simple present tense.

Don't laugh at me when I make a mistake.

Don't laugh at me when I make mistakes.

The same is true of my example above. If he comes here tomorrow, tell him to call me back. Tell him to call me back.

3。 On gerund

Gerund is easy to judge in form, that is, verb prototype +ing, if it is negative, it is not verb prototype +ing. Like to do and not to do.

One thing you should remember is that gerund is called gerund because it comes from verb, so it retains some characteristics of verb, such as bringing its own object, adverbial and so on. It can have active and passive forms and tenses. For example, for gerund, it can have general form and perfect form; Passive voice and so on. As can be seen from the name of gerund, the biggest feature of gerund is that it can be used as a noun (including the different evolution of the above-mentioned do, all of which are gerund). Therefore, judging whether the first word of a sentence is a gerund is actually very simple, depending on whether it is the form I mentioned above: do, don't do, have done, have done and are doing. They are easily distinguished from the prototype of verbs.

Cheating in exams will ruin a person's character. Cheating in exams destroys people's character.

After retirement, my father felt a sense of loss. Retirement made my father feel lost.

If you are satisfied, please accept it. I wish you progress in your studies.