Conditional Sentences

1. Definiton of Conditional Sentences
In grammar, conditional sentences are sentences discussing factual implications or hypothetical situations and their consequences. Languages use a variety of conditional constructions and verb forms (such as the conditional mood) to form such sentences.

Full conditional sentences contain two clauses: the condition or protasis, and the consequence or apodosis.

If it rains [condition], (then) the picnic will be cancelled [consequence].

2. The Types of Conditional Sentences

Conditional Sentence Type 1 :
It is possible and also very likely that the condition will be fulfilled. 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.

Conditional Sentence Type 2 :
It is possible but very unlikely that the condition will be fullfilled. 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.

Conditional Sentence Type 3 :
It is impossible that the condition will be fulfilled because it refers to the past. 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.



3. The Example of Conditional Sentences

• If John has the money, he will buy a Ferrari.
• If I won the lottery, I would buy a car.
• If he said that to me, I would run away.
• If you had called me, I would have come.
• If Gimli studies hard, he will pass the exam.
• If I see you tomorrow, I will buy you a drink.
• If I have time today, I will phone my friend.
• If I go to England, I will buy some Cheddar chese.
• If I had more time, I would do more on my websites.
• If I have the time, I will go.

Source :
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences
http://en.wikipedia.org/wiki/Conditional_sentence
http://ismailmidi.com/berita-140-conditional-sentences.html