frequently ['friːkw(ə)ntlɪ]

adv. 频繁地，经常地时常，屡次

frequent 在这里是名词

Please write to me frequently.

请经常给我来信。

Her advice has frequently been less than wholly helpful.

她的建议往往毫无帮助。

And I think it 's frequently completely unnecessary.

而在我看来，这种浪费往往毫无必要。