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If (/ɪf/) is an English word which can be used either as a subordinating conjunction or as a preposition.[1]

Preposition[edit | edit source]

If is a conditional preposition used to form if clauses, which are a type of conditional clause. It has an antonym, unless.

If can also be used with past participial adjectives, e.g. if done rather than having a full clause.

If the condition is a repeated condition, then if can be substituted with when.

Subordinating conjunction[edit | edit source]

Some usage critics recommend that if not be used to mean whether, since the distinction can remove ambiguity, as in the following example:

"Tell me if you can see her". (if the addressee can see her, then he or she must tell the speaker something)
"Tell me whether you can see her". (the speaker wants to know the positive or negative instance of the addressee's ability to see her)

This distinction is further encouraged because if cannot always be used in place of whether. For instance, if the noun clause acts as the subject of the sentence or an object of a preposition, the word must be whether. Examples:

"We like to talk about whether classical music is better than jazz". (not if classical music is better than jazz)
"Whether you like today’s weather does not matter". (not If you like today’s weather)

References[edit | edit source]