let alone   (TTS發音)

1. allow sb. to do sth. unaided；not interfere with 別管；別幹涉

    When joe gets mad，just let him alone. 喬發怒時不要去管他。

    Please let my things alone. 請不要幹涉我的事情。

2. not to mention；to say nothing of 更不用說

    I can't afford a bicycle，let alone a car. 我連一部自行車也買不起，更不用說買小轎車了。

    He doesn't have enough money for food，let alone amusements. 他連吃飯都不夠，更不用說娛樂了。

    I wouldn't speak to him，let alone trust him and lend him some money. 我理都不願理他，更談不上信任他，把錢借給他了。