Conditional Sentences

Conditional sentences are statements expressing factual implications, or hypothetical situations and their consequences. These sentences use conditional construction and verb forms, which is called the conditional mood. They are so called because the validity of the main clause of the sentence is conditional on the existence of certain circumstances, which may be expressed in a dependent clause or may be understood from the context. The tricky part about constructing a conditional sentence is it involves many factors both in its form and meaning. Since there are various factors involved when writing conditional sentences, the rules can be explained in different ways. The properties of the entire conditional sentences are determined by the condition’s tense and degree of realness.

Structure Conditional Sentence

type	if clause	main clause
I	Simple Present S + V1 + O/C	will-future (Modal + infinitive)	Real in present/ future
II	Simple Past S+Be+Was/Were/V2+O/C	would + infinitive	Unreal in present/ future
III	Past Perfect S + had + V3	would + have + past participle	Unreal in past

if-clause at the beginning

type	if clause	main clause
I	If I go,	I will meet her.
II	If I went,	I would meet her.
III	If I had gone,	I would have met her.

if-clause at the end

type	main clause	if-clause
I	I will meet her.	If I go,
II	I would meet her.	If I went,
III	I would have met her.	If I had gone,

Type Conditional Sentences

Conditional Sentence type I: condition possible to fulfill

·         to talk about a probable or certain outcome in the future, or something we believe will happen if the condition is satisfied.

·         use the present tense in the condition clause and future tense in the result clause.

Example:

If you work hard, you will get that promotion.

If it rains tomorrow, we will not go on a picnic.

If he is still sick next week, his sister will hand in his assignment.

I will fix your bicycle if I have a screwdriver of the poper size.

Jack will shave today if he has a sharp razor.

If I have time, I will come

Conditional Sentence type II: condition in theory possible to fulfill

·         to give advice or make a suggestion.

·         to talk about what would happen in a situation which is not the case at present.

·         use the past simple in the condition clause and would/could/should/might+infinitive in the result-clause.

Example:

If I were you, I wouldn't disturb him

Fact: I am not you, so I will disturb him.

If we waited a little longer, we could meet the manager.

Fact: We are not wait a little longer, so we can not meet the manager.

If Mary knew about it, she would tell me.

Fact: Mary is not know about it, so she is not tell me.

If I had enough time now, I would write a letter  to my parents.

Fact: I do not have enough time now, so I do not write a letter to my parents.

He would not come to your party if you did not invite him.

Fact: He will come to your party, because you invite him.

Conditional Sentence type III: condition not possible to fulfill (too late)

·         to talk about what would have happened in a situation which was not the case in the past.

·         use the past perfect in the conditional clause and would have/ could have /might have + past participle in the result-clause.

Example:

If you had woken up early, you wouldn't have missed your flight.

Fact:  You did not woke up early, so you were missed your flight.

If you had told me about the problem, I would have helped you.

Fact: you did not tell me about 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 umbrella with me yesterday.

Source

http://en.wikipedia.org/wiki/Conditional_sentence

http://www.grammarly.com/handbook/sentences/conditional-sentences/

Suyudi Ichwan dan Sri widianti. Bahasa Inggris 1, Edisi pertama. Jakarta: Gunadarma, 1995.

http://www.englishbaby.com/lessons/4716/member_submitted/conditional_sentences

http://www.englisch-hilfen.de/en/grammar/if.htm