English Grammar - Conditional Sentence: 56 MCQs with Answers

The conjunction ‘as if’ introduces an unreal or hypothetical comparison, and English marks such unreality by shifting the verb one tense back. Since the main clause ‘He walks’ is in the present tense, the clause after ‘as if’ must take the past form, giving ‘as if he had a wooden leg’. The sentence does not claim that he actually has a wooden leg; it only says his walk resembles that of a person who does. This is the same subjunctive-like backshift found in ‘He talks as if he knew everything’.

The zero conditional uses the simple present tense in both clauses to express general truths: 'If you heat water..., it boils.'

The zero conditional expresses a scientific fact using simple present in both clauses.

This general truth is correctly expressed using the zero conditional structure.

This general truth about plants is correctly expressed using the zero conditional.

The zero conditional structure is 'If + simple present, simple present', used for facts and general truths.

The first conditional uses 'If + simple present, will + base verb' to express a real future possibility.

This real future possibility is correctly expressed using the first conditional structure.

'If she calls, I will answer' correctly uses the first conditional for a likely future event.

This real future condition is correctly expressed using the first conditional.