1.2.3. If you would

We use would as a modal verb, which represents a more tentative (or 'polite') form of will as used in conditional clauses of Type 1. It introduces the idea of 'your' agreeing, or being willing, to do what is suggested. (see 1.1.2)

If you would reserve seats, we would be sure of a comfortable journey.

1.3. Type 3: unreal conditions (past time reference)

These sentences are completely hypothetical, and represents what is contrary to past fact.

If clause main clause

past perfect would + perfect infinitive

(simple or continuous) modal + perfect infinitive

If we had caught the 10 o'clock train, we would have got there by lunch-time.

If I had been watching the road, I wouldn’t have had the accident.

If you hadn't reminded me, I might have forgotten.

In this case, the past perfect tense is used to indicate past unreality—we didn't catch the 10 o'clock train, so we didn’t get there by lunch-time.

1.3.1. the verb to be in the if-clause

The verb to be takes the normal past perfect form had been

If I had been you / if I had been in your position I would have accepted their offer.

1.3.2. Type 3: variations

Variations of this type of sentence are not very common, though sentences like the following are occasionally met with:

If you were to have asked me, I would have been only too willing to help.

1.4. Mixed conditionals

We get a 'mixed' type of sentence, when the two clauses in a conditional sentence have a different time reference:

If Bob wasn't so lazy, he would have passed the exam easily.

(type 2 unreal present + type 3 unreal past)

If we had brought a map with us, we would know which road to take.

(type 3 unreal past + type 2 unreal present)

If the doctor had been called earlier, she would still be alive today.

(type 3 unreal past + type 2 unreal present)

If I am as clever as you say I am, I would have been rich by now.

(type 0 real present + type 3 unreal past)

2. Variation in sentence structure

2.1. Inversion:

If the first verb in a conditional if-clause is should, were, or had we can leave out if and put the verb at the beginning of the clause.

1. Should you need my help again, just give me a ring. (If you should need my help again,…)

2. Were the Government to go back on this election pledge, there would be a revolt among back-benchers. (If the Government were to go back ...)

2. It would be embarrassing, were she to find out the truth. (...if she were to find out...)

3. Had I known you were ill, I would have visited you. (If I had known you were ill,...)

3. Had they not rushed Dan to hospital, he would have died. (If they hadn't rushed Dan...)

The first and third types of inversion occur in both the written language and (though less commonly) the spoken. The second type, however, is generally confined to the written language. All occur most commonly when it is the subject in the conditional clause.

2.2. If and adjectives

In expressions such as if it is necessary/possible it is possible to omit the verb be.

If interested, apply within.

If necessary, take a taxi.