Indicates 'if' or 'when' a certain condition is met.
When to use
Stating conditions, Expressing hypotheticals, Giving advice, Making requests
The nuance
Attach to the verb or adjective stem: use '-으면' if the stem ends with a consonant, '-면' if it ends with a vowel. For past tense conditions, use '-았으면/었으면'. It expresses condition or hypothetical situations.
