CONDITIONAL SENTENCE

   1.       DEFINITION CONDITIONAL SENTENCE :

     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.

    2.       TYPES OF CONDITIONAL SENTENCES :

               a.       Zero Conditional (Conditional Sentences type 0)

    Zero conditional sentence or a conditional sentence conditional type 0 is used when the (result / consequence) of the condition (condition) is always manifested as a scientific fact or a general truth which is a habit (habitual action). Section dependent clause (if + clause) may be preceded by the words "if" or "when". 

if + simple present, simple present

            EXAMPLES :

-          If people eat too much, they get fat

-          If babies are hungry, they cry

b.      Conditional Sentence Type I

it is possible and also very likely that the condition will be fulfilled, or most likely something he is supposed to happen. Future action will only happen if certain conditions are fulfilled at the time. We do not know for sure if the actual conditions will be fulfilled or not, but certainly seems more realistic conditions so we thought it was very possible.

        if + simple present, will + bare infinitive

EXAMPLES :

-          If you give me money, I will help you

-          If you leave your sister alone, she will miss you

c.       Conditional Sentence Type 2

Conditional sentence type 2 is used to express the actions that are not possible because the condition may not be fulfilled. This sentence is used to talk about the fact that contrary to the present.

if + Simple Past, Conditional I (= would + Infinitive)

EXAMPLES :

-          If I were you, I would be very angry

-          If you followed my instructions, you would be safe

d.      Conditional Sentence Type 3

In the conditional sentence type 3, the condition may not be fulfilled because it happend in the past so that the action can not be happening. This sentence is used to discuss expectations were not realized in the past.

if + Past Perfect, Conditional II (= would + have + Past Participle)

EXAMPLES :

-          If her grandfather had been immediately taken to the hospital, he would have been saved

-          If Jono had studied hard, he would have passed the exam

SOURCE: 
http://www.ilmubahasainggris.com/conditional-sentences-type-0-1-2-3
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