6-19. Пропуски в условном предложении

 
1. При инверсии (с were, had и should) союз if опускается:

Were she my daughter, ... (= If she were my daughter ... )
Had I realized what you intended, ... (= If I had realised )
Should you change your mind, ... (= If you should change )

■ Отрицательные формы нельзя сокращать:

Had we not missed the plane, we would all have been killed in the crash. (не 'Hadn't we missed ...' )

2. If может иногда опускаться в разговорной речи:

You want to get in, you pay like everybody else. (= If you want ... )
You touch me again, I'll kick your teeth in.

■ Пропуск слов после if

В некоторых типовых случаях глагол be можно опускать – получаются короткие безличные придаточные предложения:

I'll work late tonight if necessary. (= ... if it is necessary/ if it be necessary)
We will sell the car, if necessary (= We will sell the car, if it is necessary).
If in doubt, ask for help. (= If you are in doubt ... )
This unfortunate situation is to be avoided if possible.
If I were innocent, I’d rather be tried here; if guilty, in America.
If in doubt, ask at your local library.
There is little if any good evidence for flying saucers.
I'm not angry. If anything, I feel a little surprised.
He seldom if ever travels abroad.
If about to go on a long journey, try to have a good night's sleep.