by sth for sb

by sth for sb. by sth for sb by sth.to sb.还是by sth.for sb. by sb sth 和 buy sth for sb 意思一样吗?用法一样吗? by sth ______ sbby sth ______ for sbby sth ______ to sb分别用在什么地方 sth to sb 还是 sth for sb spare sb./sth.for sb./sth. be sth for sb call sb for sth have sth for sb ask sb for sth plan sth.for sb. buy sth for sb. thank sb for sth/doing sth造句 reward sb with sth for doing sth provide sb with sth,provide sth for buy sb sth=buy sth for make sth for sb=?