off and on   (TTS發音)

not regularly；occasionally時輟時續的

    It rained off and on all day. 雨斷斷續續地下了一整天。

    He wrote to a girl in London off and on for several years. 他與倫敦的一位姑娘斷斷續續地通了幾年信。

    We don't go to the theatre regularly，just off and on. 我們不常去看戲，只是偶爾看看罷了。