buy的用法：
buy sth for+錢 :買某物花了多少錢。I bought the book for 50 yuan.
buy sth for sb=buy sb sth 給某人買某物：He bought me a new coat. =He bought a new coat for me. 他給我買了一件新外套。
buy sth from sb（for+錢）（花了多少錢）從某人那裡買了某物：
I bought it from a friend for ?0. 我從朋友那裡花10英鎊買來的。
sell的用法：
sell sb sth =sell sth to sb 賣給某人某物： He sold me the bike. =He sold the bike to me.他把腳踏車賣給我了。
sell sth for +錢：某物賣了多少錢；sell sb sth for+錢 =sell sth to sb for+錢：以多少錢把某物賣給某人：
He sold the bike for 100 yuan. 他的腳踏車賣了100元。
He sold me the bike for 100 yuan. =He sold the bike to me for 100 yuan.他以100元把腳踏車賣給了我。
sell（不及物動詞） for+錢：賣了多少錢： The bike sells for 100 yuan. 這輛腳踏車賣100元。
sell （不及物動詞）well暢銷，賣得好：The book sells well. 這本書很暢銷。
sell sth out：某物賣完了：The book has been sold out.這本書已經賣完了。
sell (sth) at a/the price of...以......價格賣（某物）：He sold the TV set at the/a price of 500 yuan.他以500元的價格把電視機賣了。
buy的用法：
buy sth for+錢 :買某物花了多少錢。I bought the book for 50 yuan.
buy sth for sb=buy sb sth 給某人買某物：He bought me a new coat. =He bought a new coat for me. 他給我買了一件新外套。
buy sth from sb（for+錢）（花了多少錢）從某人那裡買了某物：
I bought it from a friend for ?0. 我從朋友那裡花10英鎊買來的。
sell的用法：
sell sb sth =sell sth to sb 賣給某人某物： He sold me the bike. =He sold the bike to me.他把腳踏車賣給我了。
sell sth for +錢：某物賣了多少錢；sell sb sth for+錢 =sell sth to sb for+錢：以多少錢把某物賣給某人：
He sold the bike for 100 yuan. 他的腳踏車賣了100元。
He sold me the bike for 100 yuan. =He sold the bike to me for 100 yuan.他以100元把腳踏車賣給了我。
sell（不及物動詞） for+錢：賣了多少錢： The bike sells for 100 yuan. 這輛腳踏車賣100元。
sell （不及物動詞）well暢銷，賣得好：The book sells well. 這本書很暢銷。
sell sth out：某物賣完了：The book has been sold out.這本書已經賣完了。
sell (sth) at a/the price of...以......價格賣（某物）：He sold the TV set at the/a price of 500 yuan.他以500元的價格把電視機賣了。