CONDITIONAL - IF CLAUSES

CONDITIONAL-IF

Conditional Sentences are also known as Conditional Clauses or If Clauses. They are used to express that the action in the main clause (without if) can only take place if a certain condition (in the clause with if) is fulfilled. There are three types of Conditional Sentences. There is four type on conditional clauses, such as:

1.      Conditional Sentences Type 0

Conditional type zero is used to talk about general truths, scientific facts or things which always happen under certain conditions. The tense in both parts of the sentence is the simple present. In zero conditional sentences, the word "if" can usually be replaced by the word "when" without changing the meaning. The zero conditional is used to talk about things which are always true, scientific facts, general truths.

Form : If + Simple Present, + Simple Present

Example:

·         If you cross an international date line, the time changes.

·         Phosphorus burns if you expose it to air.

·         If I wake up early, I go jogging.

2.      Conditional Sentences Type 1

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.

Form :if + Simple Present, will-Future

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.

·         I will send her an invitation if I find her address

Note : Main clause and or if clause might be negative. See Simple Present and will-Future on how to form negative sentences.

·         If I don’t see him this afternoon, I will phone him in the evening.

3.      Conditional Sentences Type 2

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 …“

Form : if + Simple Past, main clause with Conditional I (= would + Infinitive)

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.

·         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.

·         If I had a lot of money, I wouldn’t stay here.

Were instead of Was, In IF Clauses Type II, we usually use ‚were‘ – even if the pronoun is I, he, she or it –.

If I were you, I would not do this.

4.      Conditional Sentences Type 3

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.

Form : if + Past Perfect, main clause with Conditional II

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.

·         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.

·         If I hadn’t studied, I wouldn’t have passed my exams.

Source: https://www.ego4u.com/en/cram-up/grammar/conditional-sentences