1) 大部分形容词加-ly 可构成副词。但 friendly，deadly，lovely，lonely，likely，lively，ugly，brotherly，仍为形容词。
改错：(错) She sang lovely.
(错) He spoke to me very friendly.
(对) Her singing was lovely.
(对) He spoke to me in a very friendly way.
2)有些以-ly 结尾既为形容词，也为副词。
daily，weekly，monthly，yearly，early
The Times is a daily paper.
The Times is published daily.