if

conjunction

1》 introducing a conditional clause:

    ↘on the condition or supposition that.

    ↘(with past tense) introducing a hypothetical situation.

    ↘every time.

2》 despite the possibility that.

    ↘despite being.

3》 whether.

4》 expressing a polite request or tentative opinion.

5》 expressing surprise or regret.

noun a condition or supposition.

Phrases

if and only if used to introduce a condition which is necessary as well as sufficient.

if anything used to suggest tentatively that something may be the case.

if not perhaps even (used to introduce a more extreme term than one first mentioned).

if only even if for no other reason than.

if so if that is the case.

Origin

OE gif, of Gmc origin.