Look at these examples to see how third and mixed conditionals are used.
We would have walked to the top of the mountain if the weather hadn't been so bad.
If we'd moved to Scotland when I was a child, I would have a Scottish accent now.
If she was really my friend, she wouldn't have lied to me.
Try this exercise to test your grammar.
- Grammar test 1
Read the explanation to learn more.
Grammar explanation
Do you know how to use third and mixed conditionals?
Third conditionals and mixed conditionals
Conditionals describe the result of a certain condition. The if clause tells you the condition (If I hadn't been ill) and the main clause tells you the result (I would have gone to the party). The order of the clauses does not change the meaning.
If I hadn't been ill, I would have gone to the party.
I would have gone to the party if I hadn't been ill.
Conditional sentences are often divided into different types.
Third conditional
The third conditional is used to imagine a different past. We imagine a change in a past situation and the different result of that change.
If I had understood the instructions properly, I would have passed the exam.
We wouldn't have got lost if my phone hadn't run out of battery.
In third conditional sentences, the structure is usually: If + past perfect >> would have + past participle.
Mixed conditionals
We can use mixed conditionals when we imagine a past change with a result in the present or a present change with a result in the past.
1. Past/Present
Here's a sentence imagining how a change in a past situation would have a result in the present.
If I hadn't got the job in Tokyo, I wouldn't be with my current partner.
So the structure is: If + past perfect >> would + infinitive.
2. Present/Past
Here's a sentence imagining how a different situation in the present would mean that the past was different as well.
It's really important. If it wasn't, I wouldn't have called you on your holiday.
And the structure is: If + past simple >> would have + past participle.
Do this exercise to test your grammar again.
- Grammar test 2
Hello again Vitub,
Before we look at your particular example, you need to make sure that thes structures you are looking at are the same. You need to check if the to is part of an infinitive or is a preposition, for example, and if it is an infintive whether or not it is functioning as a verb in the sentence or is being used as the subject or object of the clause in the same way that a gerund can be.
All that said, let's look at your example.
In this example, to be different is used as a concept, not an action. In other words, it functions as the subject of the verb is. You could put quotes around it to make this clearer:
You could also replace it with a gerund:
In other words, you do not have a verbal expression here, but an infinitive functioning as the subject of the sentence. Infinitives are often used this way:
Generally, the infinitive form in these constructions is more conceptual, equivalent to saying 'the idea of....'. The gerund is more concrete, describing actual actions.
The other example you quote (about calculating work duration) does not appear to me to be correct English. I have no idea who the author is and if they are a fluent English speaker, or even if they typed what they intended. This is why finding examples online in forums and treating them as a good source is not a sensible approach. Examples in published materials from reputable publishers, such as the Cambridge Plato translation, are far better.
Peter
The LearnEnglish Team
Hello Ahmed Imam,
The sentence is unusual, but correct. We can use a negative form after unless when it describes something that we do not expect. In other words, in your example the speaker believes Mary is studying or will study.
Here are a few more examples:
Note that a positive verb is needed in the first clause. We do not use a negative verb with unless and another negative verb.
Peter
The LearnEnglish Team
Hello Vitub,
The language in your quote has many mistakes. It looks like it was translated from another language via an online translation application, to be honest.
Peter
The LearnEnglish Team
Hello again Vitub,
There's a few things to unpack here.
First of all, I didn't say that you used a translation app. I was commenting on the source you provided. I looked at the patent application (your source) and saw that it was full of errors. It is not a reliable source for language.
The quote you provided (And the amount that adds water is important parameter of the present invention, if it is many to have added water, material thinning being difficult to granulate, and if to add water few, expect dry dust and the difficult granulating of also easily producing.More suitable water consumption is the 15-25% of formula total amount...) is something produced, in my opinion, by an app. It is, frankly, horrible English, and the use of if + to is not correct.
Your other example is different. I'll address this in answer to your other comment.
Peter
The LearnEnglish Team
Hello CareBears07
As Swan mentions in the following sentence, 'if' can be used in many situations, not just those that teachers often call zero, first, second, third and mixed conditionals. (I'm not sure what edition you have, but if it's the third edition, read on to section 257. I'm not sure where he explains this in other editions.)
Particularly when the 'if' clause does not refer to an imaginary situation -- which seems to be the case in the sentence you cite -- all kinds of verb tenses can be used. In other words, this sentence could mean that we know that she did not phone this morning, and since she did not phone this morning, one possible explanation for this is that she's away.
Hope this helps.
All the best
Kirk
The LearnEnglish Team