if

if ► CONJUNCTION 1) introducing a conditional clause; on the condition or supposition that. 2) despite the possibility or fact that. 3) whether. 4) every time that; whenever. 5) expressing a polite request or tentative opinion. 6) expressing surprise or regret.

► NOUN ▪ a condition or supposition.

● if anything — Cf. ↑if anything

● if only — Cf. ↑if only

● if so — Cf. ↑if so

USAGE If and whether are more or less interchangeable in sentences like I'll see if he left an address and I'll see whether he left an address, although whether is more formal and more suitable for written use.

ORIGIN Old English.