buy一个常用的英语动词，表示“购买”、“买入”的意思。除了常见的buy something（买某物）之外，还有一些常用的buy短语，如buy into、buy off、buy out、buy up等。以下是这些短语的用法和拓展：

一、buy into

buy into表示“相信”、“接受”、“参与”等意思。例如：

I don't buy into his argument.（我不相信他的论点。）

She bought into the company's vision and became a loyal employee.（她接受了公司的愿景，成为了一名忠诚的员工。）

二、buy off

buy off表示“贿赂”、“收买”等意思。例如：

The politician was accused of trying to buy off the opposition.（这位政治家被指控试图收买反对派。）

The company tried to buy off the environmental activists with a donation.（公司试图通过捐赠来收买环保活动人士。）

三、buy out

buy out表示“买下”、“收购”等意思。例如：

The company bought out its competitor and became the market leader.（公司收购了竞争对手，成为了市场领导者。）

The partners decided to buy out the other shareholders and take full control of the company.（合伙人决定买下其他股东的股份，完全掌控公司。）

四、buy up

buy up表示“买光”、“抢购”等意思。例如：

The store bought up all the available stock of the popular toy.（商店买光了这种热门玩具的所有库存。）

Investors are buying up properties in the city center.（投资者正在抢购市中心的房产。）