Do you know how to use third and mixed conditionals?

Third conditionals and mixed conditionals

Conditionals are sentences with two clauses – an if clause and a main clause – that are closely related. Conditional sentences are often divided into different types.

Third conditional

Third conditional sentences describe the past. They describe something that didn't happen.

  • If I'd studied harder at school, I would have gone to university.

He didn't study very hard and he didn't go to university.

  • We wouldn't have got lost if you hadn't given me the wrong directions.

She wasn't given the correct directions and she didn't find her way.

  • She might have finished the exam if she'd had more time.

She didn't finish the exam and she didn't have more time.

In third conditional sentences, the structure is usually if + past perfect and would + perfect infinitive (e.g. have done). It's not important which clause comes first.

Notice that other modal verbs can be used instead of would (e.g. could, might, may)

Mixed conditionals

In mixed conditional sentences the time in the if clause is not the same as the time in the main clause. There can be various combinations.

  • If he'd gone to university, he might have a better job.

He didn't go to university (past)
He doesn't have a very good job. (present)
This sentence shows the present consequences of a past action.

  • If I'd won the competition, I'd be going to Florida next week.

She didn't win the competition (past)
She isn't going to Florida (future)
This sentence shows the future consequences of a past action.



Language level

Upper intermediate: B2


thank you so much, teacher Kirk!

That clears everything for me about these sentences :)

Dear,teacher Kirk.

I am sorry to bother you again. I forgot to ask the third sentence ( 'If I kissed the girl, I will have to apologize to her').

It isn't indicate a hypothetical situation, is it?

I mean : does the sentence gives you impression that ' I did kiss the girl , or at least, I am convinced that I did kiss the girl in the past , and now I regret it and I realize I must then apologize to her' ?
Thank you so much again.

Hello again jiyi,

This third sentence would not be correct in most situations. If the if-clause refers to a hypothetical situation, as it seems to do here, the other clause needs some kind of conditional verb (e.g. 'would'). For example, 'If I kissed the girl, I would have to apologise'.

If, however, the speaker is speaking about the past, for example, admitting that they possibly don't remember their actions, then this sentence could be grammatically correct. It would mean something like 'I don't think I kissed the girl, but if I did, I will have to apologise to her'.

All the best,
The LearnEnglish Team

dear teacher,
Thank you so much for replying. It was actually a post in this comment section from August 2016.

btw, I am sorry, but I have to ask help again. I just want to clarify some :

1. Actually, I am already aware about the tricky part of ' have ' as you've mentioned. But I am having difficulty to understand where these sentences belong to. For instance, If I didn't want to make a third conditional with my first sentence ( If I had kissed her, I would have to..)

is it structurally a mixed conditionals ( a combination of 3rd and 2nd conditional)?

because from my point of view, the clauses in that sentence have different time period (one in the past and the other one is in the future) and I was also using 'have to' as a way to talk obligation instead of using it to make a perfect form, is it true?

2. And for the second sentence ( If I kissed.., I would have to..).

If this is a correct sentence, then is the meaning of that sentence functioning like a 2nd conditional ('if I kissed..' as a present or future hypothetical situation-->meaning: if I ever kiss the girl someday, then i must apologize to her)?

sorry for bothering you, I need such clarification because I found that this way is what works well for my studying.
Thank you again.

Hi again jiyi,

Sentence 1 is indeed a mixed conditional (with third conditional in the first part and second conditional in the second part) and it is grammatical. 'had kissed' refers to an action that could have happened in the past (but did not) and 'would have to apologise' refers to an imaginary action in the present or future (that also isn't happening).

Sentence 2 is a second conditional construction, with a verb in the past simple ('kissed') in the 'if'-clause and 'would' + base form in the other clause. Your explanation correctly explains the idea of the sentence.

All the best,
The LearnEnglish Team

Dear teachers,
I,ve read a few of the comments here but I am having difficulty to understand some of the examples given:

1. 'If I had kissed the girl, I would have to apologize to her.'
I had a debate with my friend last night because she thought that this is a 3rd conditional (because of the 'would have') , but I think that this is more like a mixed conditionals, am I right?

2. You said that: 'If I kissed the girl, I would have to apologize to her' is wrong, because it combines real and unreal situation. I don't really get it. Can you please explain this with more details(which one is real and unreal) ?

I thought that this was true because it follows a 2nd conditional ( and I think the questioner was thinking about present hypothetical situation) ?
But you gave another example instead:

'If I kissed the girl, I will have to apologize to her.'
which obviously has different meaning( not hypothetical).

Please help me to understand this. I am confuse. Thank you very much :)

Hi jiyi,

I'm afraid I can't find the examples you are speaking of on this page. In sentence 1, the second verb would need to be 'would have had' for it to be a full third conditional structure. Sentence 2 looks correct to me.

I think what might be confusing you is the form 'to have to', which indicates obligation. It can be confusing, because 'have' is also part of the 'would have + past participle' form that is used in the third conditional. If you changed the second part to just 'apologise' (instead of 'have to apologise'), then you'd get:

1st conditional: If I kiss her, I will apologise
2nd conditional: If I kissed her, I would apologise
3rd conditional: If I had kissed her, I would have apologised

I hope that clears it up for you.

All the best,
The LearnEnglish Team

Could you please explain" wouldn't+ verb"? For example:
I wouldn't leave the office until I had checked that all the doors were locked.
My question is: shouldn´t we use "didn't leave" instead of "wouldn´t leave" or is it correct as it is.
Thank you.

Hello Ahmed Imam,

What is correct here depends on the situation and what the speaker means. If this sentence is about a specific past action, then you are right, 'didn't leave' is the best form. 'would' can be used to speak about past habitual actions, however, so it is actually possible to use it here if that's what the speaker means.

All the best,
The LearnEnglish Team