Often is usually used before the verb, but it may be used after the verb when it has a word like ‘less’ or ‘more’ before it, or when the clause is negative.
often通常用于动词前，但若前面有less，more等词，或从句为否定形式时，可置于动词之后。
often 基本解释
1. as often as : 每当；
2. every so often : 不时；
3. often and often : 经常；
