Meaning of cài:
菜
vegetable; greens (CL:棵[ke1]); dish (of food) (CL:樣|样[yang4],道[dao4],盤|盘[pan2]); (coll.) (one's) type
Jīntiān wǒ mǎi le hěn duō xīnxiān de cài.
今天我买了很多新鲜的菜。
Today I bought a lot of fresh vegetables.
Jīntiān de tèsè cài shì mápó dòufu.
今天的特色菜是麻婆豆腐。
Today's special dish is Mapo Tofu.
Zhè wèi gēshǒu zhènghǎo shì wǒ de cài.
这位歌手正好是我的菜。
This singer is exactly my type.
(of one's skills etc) weak; poor
Nà wèi gēshǒu de chànggōng hěn cài.
那位歌手的唱功很菜。
The singer's singing skills are really weak.