An if clause (/ɪf klɔ:z/) is a type of conditional clause that begins with the adverb "if". Note pedagogic grammar may refer to an "if clause" when it technically referring to its hypernym, the far more general conditional clause, as the term "if clause" is more intuitively understood by students.
Roughly, there are three types:
- "If I go to the park, …" present simple or present continuous, used in the zero conditional and the first conditional.
- "If I went to the park, …" past simple, used in the second conditional.
- "If I had gone to the park, …" the past perfect simple, used in the third conditional and the mixed conditional.
There are other ways of forming conditional clauses, such as an unless clause.