Conditional Sentences

Conditional sentences are sentences expressing factual implications, or hypothetical situations and their 

consequences.

There are 3 kinds of conditional sentences :

1.    future conditional sentences (type 1)

used to telling or hoping a wish, a hope or a plan that might be happen one day.

form  : If + Subject + verb 1/es ,  Subject + will + verb 1

                     Subject + will + verb 1,  If + subject + verb 1/s/es

          ex      : If I have time, I will go to Chelsi’s party.

2.    Present conditional sentences (type 2)

conditional phrases used to express unfulfilled wishes, hopes, or plans, or fancy wishes that contradict the current facts.

form  : If + Subject + Verb 2, Subject + Would + Verb 1

            Subject + Would + Verb 1, If + Subject + Verb 2

ex      : If I had time, I would go to Chelsi’s party.

3.    Past conditional sentence (type 3)

used to assume events, wishes, hopes or plans that are no longer possible, because the actual events have occurred in the past.

form  : If + Subject + Had + Verb 3, Subject + Would/Could/Might + Have + Verb3

          Subject + Would/Could/Might + Have + Verb3, If + Subject + Had + Verb 3.

ex      : If she had got the money, she would have bought a car.

Conditional Sentences without “IF”

We can also make conditional clauses without if.

Study the examples given below.

·         If I had known his real motive, I wouldn’t have supported him.

We can express the same idea without if.

·         Had I known his real motive, I wouldn’t have supported him.

Another example is given below.

·         If I had realized the importance of physical training, I would not have wasted my time in front of the television.

The above sentence can also be written as:

·         Had I realized the importance of physical training, I would not have wasted my time in front of the television.

·         If problems arise, we will seek professional help.

The same idea can be expressed without if.

·         Should problems arise, we will seek professional help.

We can also make conditional forms by putting ‘were’ at the beginning of the sentence.

·         Were I you, I wouldn’t permit this. (= If I were you, I would not permit this.)

Conditional sentences can also be made with unless.

·         Unless you work hard, you will not pass. (= If you do not work hard, you will not pass.)

Source : Tumijo, 2009. Successful Strategies for Toefl. Pustaka Widyatama : Yogyakarta

https://www.englishgrammar.org/conditional-clauses/