5.1. Придаточные предложения условия

a) Present Simple + Future Simple If they strike form, they'll win. (Perhaps they will strike form, perhaps not.) If this spell continues, it will be necessary to stop work.(It may become necessary, it may not.) These are possible future events.

b) Past Simple + условное наклонение If we arrived early, they wouldn't score at all. (But we probably won't.) I'd have to start again if they rejected my thesis. (Though it's unlikely.) These are possible but improbable future events.

If I were you, I would take a holiday. (But of course I am not you.) John would help us if he were here. (John's away.) If you managed the team, we'd never lose. (But of course you don't now, and never will.) These are imaginary hypotheses about present or future events; they cannot happen. Note the use of 'were' after 'I', 'he'; I/he/she/it was, in an 'if clause, usually become If I/he / she / it were ... .

If you took the boat tonight, you would be home tomorrow. This is neither impossible nor unlikely, but an open possibility like sentence type (a); for polite suggestions of this kind, however, type (b) is usually used.

c) Past Perfect + условное наклонение

If I had not had a lot of work to do, I would have gone mad. (I didn't go mad, because I bad a lot of work.) They would have finished the platforms by now if the weather had broken. These are hypotheses about the past. It is impossible to change what happened now.

N.B. Though there are some exceptions (e. g. polite formulae: If you will / would be so kind, etc.) 'will' and 'would' are used in the main clause, not in the 'if' clause. See also Programme 6 Note 2.

The conditional form 'would' is generally used for all persons, though 'I / we should' is also used sometimes, especially in more formal written English.

5.2. Придаточные предложения условия с союзами on condition (that) / provided (that) / assuming (that) / as long as / unless

a) on condition (that) / provided (that) / assuming (that) / as long as They will achieve their object, provided the weather breaks. (But only then.) Assuming no more snags arise, they will accomplish their aim. (Only if there are no more snags.) As long as they don't reject my thesis, I'll be leaving. (But I can't if they do.) On condition (that), provided (that), assuming (that), as long as are all alternatives for 'if'; generally they are more emphatic and suggest 'only if'.

They usually occur in the Present+ Future tense form, though they may be reported: He said he would go on condition that we paid for him.

b) unless They won't win unless there is a miracle. (They'll win only if ...) Britain's position will deteriorate unless oil revenue rescues her. We'll miss the kick off unless you hurry. (If you don't hurry.) 'Unless' is usually equivalent to "if + 'not', and is often more emphatic. The 'unless' clause usually comes second.

5.3. Наречие already

Is it two o'clock already? (I thought it was only one-thirty.) I hear from Patrick he's finished his Ph. D. already. (He did it very quickly.) 'Already' is normally placed before the verb in affirmative sentences while 'yet' is used in questions: Have you finished yet? Yes, I've already finished. However, 'already' can also fall at the end of a question or statement, showing the speaker's surprise at rapid results or passage of time. Note the emphatic intonation used.