柯林斯词典comma /ˈkɒmə/ (commas) 1. N-COUNT A comma is the punctuation mark , which is used to separate parts of a sentence or items in a list. 逗號 返回 comma剑桥词典the symbol , used in writing to separate parts of a sentence showing a slight pause , or to separate the single things in a list 逗號（，） 範例 Put a comma after the clause .We usually put a comma after thousands in numbers .Should I put a comma before the 'and'? 返回 comma