conditional sentences

CONDITIONAL SENTENCES

I.    Present tense        future tense            real in  present/future
II.    Past tense         past future            unreal in present/future
III.    Past perfect        past future perfect        unreal in past

Conditional sentence type 1 :
if + Simple Present, will-Future
Examples :
i will fix your bicycle if i have a screwdriver of the proper size.
Jack will shave today if he has a sharp razor
Example : If I find her address, I will send her an invitation.
The main clause can also be at the beginning of the sentence. In this case, don't use a comma.
Example : I will send her an invitation if I find her address.
Note: Main clause and / or if clause might be negative. See Simple Present und will-Future on how to form negative sentences.
Example : If I don’t see him this afternoon, I will phone him in the evening.

Conditional Sentences Type I refer to the future. An action in the future will only happen if a certain condition is fulfilled by that time. We don't know for sure whether the condition actually will be fulfilled or not, but the conditions seems rather realistic – so we think it is likely to happen.
Example : If I find her address, I’ll send her an invitation.
I want to send an invitation to a friend. I just have to find her address. I am quite sure, however, that I will find it.
Example : If John has the money, he will buy a Ferrari.
I know John very well and I know that he earns a lot of money and that he loves Ferraris. So I think it is very likely that sooner or later he will have the money to buy a Ferrari.


Conditional sentence type 2 :
if+ Simple Past, main clause with Conditional I (= would + Infinitive)
Examples :
If i had enough time now, i would write to my parents.
Fact: i do not have enough time now, so i do not write to my parents.
He would not come to your party if you did not invite him.
Fact : he will come to party, because you invite him.
Example : If I found her address, I would send her an invitation.
The main clause can also be at the beginning of the sentence. In this case, don't use a comma.
Example : I would send her an invitation if I found her address.
Note: Main clause and / or if clause might be negative. See Simple Past und Conditional I on how to form negative sentences.
Example : If I had a lot of money, I wouldn’t stay here.

Conditional Sentences Type II refer to situations in the present. An action could happen if the present situation were different. I don't really expect the situation to change, however. I just imagine „what would happen if …“
Example : If I found her address, I would send her an invitation.
I would like to send an invitation to a friend. I have looked everywhere for her address, but I cannot find it. So now I think it is rather unlikely that I will eventually find her address.
Example : If John had the money, he would buy a Ferrari.
I know John very well and I know that he doesn't have much money, but he loves Ferraris. He would like to own a Ferrari (in his dreams). But I think it is very unlikely that he will have the money to buy one in the near future.




Conditional sentences type 3 :
if + Past Perfect, main clause with Conditional II
Example :
if you had told me about the problem, iwould have helped you.
Fact : you did not tell me about the problem, so i did not help you.
I would not have got wet yesterday if i had remembered to take umbrella with me yesterday.
Fact : i got wet, because i did not remember to take my umbrella with me yesterday.
Example : If I had found her address, I would have sent her an invitation.
The main clause can also be at the beginning of the sentence. In this case, don't use a comma.
Example : I would have sent her an invitation if I had found her address.
Note: Main clause and / or if clause might be negative. See Past Perfect and Conditional II on how to form negative sentences.
Example : If I hadn’t studied, I wouldn’t have passed my exams.

Conditional Sentences Type III refer to situations in the past. An action could have happened in the past if a certain condition had been fulfilled. Things were different then, however. We just imagine, what would have happened if the situation had been fulfilled.
Example : If I had found her address, I would have sent her an invitation.
Sometime in the past, I wanted to send an invitation to a friend. I didn't find her address, however. So in the end I didn't send her an invitation.
Example : If John had had the money, he would have bought a Ferrari.
I knew John very well and I know that he never had much money, but he loved Ferraris. He would have loved to own a Ferrari, but he never had the money to buy one.




NOTE:
In writing conditional sentences, we may put the “IF Clause” before “RESULT Clause” and vice versa.
However, we must put comma (,) at the end of the “RESULT Clause” if the “IF Clause” is put before the “RESULT Clause”
Also, the meaning of the fact must be on the contrary with the conditional sentence. Si, if the conditional sentence is in positive form, the fact will be in negative one and vice versa.