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。
2）有些以-ly 結尾既為形容詞，也為副詞，如daily，weekly，monthly，yearly，early等。例如：
The Times is a weekly paper. 《時代周刊》為周刊。
The Times is published weekly. 《時代周刊》每週發行一期。
改錯：
1.She sang lovely.
2.He spoke to me very friendly
3.Her singing was lovely.
4.He spoke to me in a very friendly way.