were having是过去进行时,表示过去某个时间正在做什么,如:we were having a meeting when the boss came in are having是现在进行时,表示说话时正在做的事,如:we are having breakfast will have是将来时,表示将来将发生的事情,如:we will have a meeting tomorrow morning have是一般现在时,表示事物的常态,如:we have English class every day