Strong是“强大的”，suit是“西服、套装、同花色的纸牌”。Strong suit是什么意思呢？请看对话：

    A: My computer crashed last night and I can’t even restart it. Could you come over and help me fix it?

    B: Sorry, but that isn’t my strong suit.

    A: Mary said you fixed her computer the other day.

    B: Well, sorry. I’m trying to focus on finishing off some other things. I will try and help you out this afternoon. But I can’t promise I will fix it.

    Note: “Strong suit” is an expression derived from card-playing, in which hearts, diamonds, clubs and spades are the suits. Figuratively, “strong suit” is an asset of special worth or utility, while the original meaning is “a long suit including high cards.” When you put your best foot forward you play your strong suit. If something is your strong suit, you are really good at it.