2.3. Grammar. Conditionals. How many types are there? Many students will be disappointed to find out that there are literally hundreds of conditional types. One expert claims that there are 372 possible kinds! The idea of there being type zero, one, two and three, is only a method grammarians use to simplify the grammar. What are the most common forms? Traditional grammar books explain the above four types like this:

Zero conditional: (If + subject + verb in present simple......) , (subject + present simple.......)

Example: If someone comes to my place, I show them puppies. (Normal consequences and natural circumstances.)

First conditional: (If + subject + verb in present simple......) , (subject + future simple.........)

Example: If you come to my place, I will show you my puppies.

Second conditional: (If + subject + past simple...................) , (subject + would + bare infinitive)

Example: If you came to my place, I would show you my puppies.

Third conditional: (If + past perfect .................) , (subject + would + have + past participle of verb)

Example: If you had come to my place, I would have shown you my puppies.

 

The differences in meaning are as follows: Zero. People often come to my place, when they do, I show them my puppies. (i.e. it is a normal thing to do.)

First: I am inviting you, and you are probably going to come.

Second: It is improbable that you will come, but if you do.... puppies.

Third: (past situation) You didn’t come, which is why you didn’t see any puppies.

 

Often there is little difference between the zero and the first, except that the zero expresses the idea of natural consequences for things that always, or habitually happen, and the first expresses a single action. Compare: If you break the school rules, we expel you.. (We expel everyone who breaks them.) If you break the school rules, we will expel you. (Headmaster talking to an individual about his behaviour.) 

The difference between the first and the second is perhaps a little more marked. The emphasis is on whether the situation is real or not, or whether it is probable or improbable. ‘If I go to the beach this weekend.... (probable/possible) ‘If I were the first man on Mars....’ (very improbable/impossible). This is why this is such a common type of phrase; if you walk into any British pub, you will hear people say phrases such as: ‘If I were in the Liverpool football team, I’d...’ You are not. You are forty-five years old, fat, and in rotten physical condition. ‘If Claudia Schiffer were my girlfriend... She’s not. Beryl Schiffer, who works in the fish factory, is your girlfriend. You’re drunk!

A common mistake is for students to think that the second conditional is for past situations. It isn’t. It contains the past simple, yes. But the idea is in the future. ‘If I went on a Caribbean cruise next year, I’d be so happy. (Future.) The reason for this is that the past simple is arguably the same as the past subjunctive tense. There are other similar ‘unreal’ forms in English. ‘If only I were famous...’  ‘I wish I was rich...’ means you are not (or were not) famous or rich, but would like to be now. This is very similar to some tenses used in romance languages to talk about unreal or hypothetical situations. Spanish expresses the idea as ‘Si fuera rico...’  Italian has similar structures. French uses the indicative in its past form too, ‘Si j’étais riche...’

The only way to express past actions is with the third conditional, which always contains the past perfect (not the past simple).

As mentioned above, this idea of zero, first, second, and third conditionals is a simplification. Different past , present and future tenses can be mixed with almost any combination of different modal auxiliary verb. This gives dozens of possible varieties. Look at these different, but simple combinations:

                If she arrives, tell her that I’ve gone home. (Present + imperative)

                If he hadn’t stolen my bike, I wouldn’t be walking at the moment. (Past action + present conditional)

                If he has killed once, he might kill again. (Present perfect + modal of possibility)

Conclusion. Complete domination of conditionals depends on two important factors. (1) A complete understanding of the differences between normal consequences, possible / probable actions, impossible / improbable actions, and past situations. (2) A complete understanding of how modal verbs function.

As this is one of the main areas of difficulty, it might be a good idea to make a brief list of uses of these modal auxiliaries, although we will look at them in much more detail in the following chapters. RECOMMENDATIONS AND ADVICE should, shouldn’t, ought to, oughtn’t to (present) should have + past participle, ought to have (past actions) OBLIGATION/ PROHIBITION must, have (got) to, need to, mustn’t, don’t have to, don’t need to, needn’t (present) had to, to not be allowed/ permitted/ prohibited, didn’t have to, didn’t need to, needn’t have (past). DEDUCTION/ POSSIBILITY/ IMPOSSIBILITY must, could, may, might, can’t (present) must have + p.part. could have + p.part., may have + p.part., might have + p.part., can’t have + p.part., couldn’t have + p.part. (past)  PERMISSIONcan, may (present) could (past)  ABILITY can, to be able to (present) could, was/were able to (past)