是用in the sofa还是on the sofa?

是用in the sofa还是on the sofa? 是sit in the sofa 还是sit on the sofa? in the sofa 还是 on the sofa? 是on the sofa还是in the sofa?我记得也是in the sofa, 我坐在沙发上是 I sit in the sofa.还是 I sit on the sofa. on the sofa还是on a sofa on the sofa还是in the sofa on the bed还是in the bed on the chair还是in the chairon the sofa还是in the sofa on the bed还是in the bed on the chair还是in the chair?急!~~~在什么情况下用in什么情况下用on呢?请高人指点啊·· 呆在沙发上是on the sofa还是 in the sofa?I'm staying _______the sofa.请问横线上应该填什么,并说说理由. in the sofa还是on the sofa如果可以,请说为什么? 是in the afternoon of April 30th 还是 on the afternoon of April 30th on the sofa还是on sofa对?为什么？ in the sofa 与on the sofa的区别 My keys are on the sofa.对on the sofa 提问?是用where are my books 还是用where are your books where is my book ? It is in the sofa.在沙发上是用in 还是on 在具体某一天的早上用什么介词啊,是in还是on?（是写in还是on）the morning of April 18th. sofa前的介词到底是什么~sofa前的介词我记得老师说过,可以用on也可以用in的,因为沙发是软的可以陷下去.那么jump into the sofa不对么? They are in the living room,on the sofa.中on the sofa 作什么成分? on the sofa 是词组吗