1） 大部分形容詞加-ly可構成副詞。但 friendly，deadly，lovely，lonely，likely，lively，ugly，brotherly，仍為形容詞。
改錯：(錯） she sang lovely.
（錯） he spoke to me very friendly.
（對） her singing was lovely.
（對） he spoke to me in a very friendly way.
2）有些以-ly 結尾既為形容詞，也為副詞。
daily，weekly，monthly，yearly，early
the times is a daily paper.
the times is published daily.