buy 后面直接跟名词就可以：My mom buys vegetables from the supermarket. 我妈妈从超市买菜。 过去式：bought 过去分词：bought buy in: 说服，接受，美剧里面常用。 I didn't buy in. 我不买你的账。也就是你的说法我不接受。

buy [baI; bai] (bought[b)t; b):t]) 及物动词 1 买 (←→ sell) a. 购,买 ~ a book 买书 You cannot ~ love. 爱情是买不到的 b. [在场所] 买[at]; 买[自…], [从[向]…] 买[from]; 买[at, for] ~ a thing at a store [from a person] 在商店[向人]买东西 I bought this ball pen for two dollars. 我花二美元买了这支原子笔 She bought the apples at seventy cents each. 她以每颗七角美元买了那些苹果 c. 买 ~ a thing cheap 买东西买得便宜 d. 为买; 买[给人][for] I bought her a new purse. = I bought a new purse for her. 我给她买了一顶新皮包 I must ~ myself a new coat. 我必须给自己买一件新外套 e. 给买 I bought him a car cheap. 我给他买汽车买得便宜 [我便宜地给他买了汽车] 2 有助于买…,能买,买得到 Money cannot ~ happiness. 金钱买不到幸福 3 请 I'll ~ you lunch. 我请你吃午餐 4 收买,笼络,买通,贿赂 (bribe) 5 (付出代价) 获得 Victory was dearly bought. 胜利是付出很高的代价获得的 6(俚)相信,接受 I don't ~ it. 我不相信这件事 不及物动词 买东西,购物 buy back 把再买回 buy in (1) (看涨行情而) (大量) 买进 (2) (于拍卖上开价低或无人买时) 再买回 buy into (1) 大量买进的股票,成为…的股东 (2) (花钱) 成为之董监事 buy it (1)(英俚) (因无法解答猜谜、问题等而) 放弃, 撒手,认输 I'll ~ it. 我服输了 (2)(俚)被杀 buy off 给钱打发走 ; 花钱摆平 [摆脱] …,花钱消 buy out 收买 的股份 [股权 (等) ] buy over 收买,向行贿,买通 We bought him over to our side. 我们收买他成为我们的人 buy up (1) 把全部买光 (2) 买下 可数名词 (口语) 1 买进,购买 2 a. 购买之物 a bad ~ 买得不便宜 [不合算] 的东西 a good ~ 买得便宜的东西,廉价品 b. 廉价品,非常合算的交易 (bargain)