is an adjective that means ‘good’ in Japanese. It can be a little bit difficult to use at first, as it conjugates differently to other い-Adjectives
In these sentences, we can see that the first い in いい
changes to よ, depending on the form. This is unique to いい
, and does not happen with other adjectives.
can sometimes be seen as 良（よ）い
, in these cases, the kanji is likely to be read as よい, and not いい. There is technically no difference between these two meanings, but よい
does sound more formal/old-fashioned.
When used as an adverb, よく should not be confused as a conjugation of いい. よく has several possible kanji that it may stem from, and means frequently/often/well.