新概念英语1第59课Is that all?中前面用we为什么后面用I

All that I want is a room somewhere 这个句子中为什么用is 新概念第一册中109课that was very nice为什么用过去式 在新概念英语第四课中,so he is finding this trip very exciting.为什么用现在式i 新概念英语第一册第69课中My wife and I were at the race.这个地方为什么要用at the She is shoet and she has long hair .中为什么前面用is,后面用has. 为什么We find it necssary that we speak English中it后面不加is? All that I can do is to wait here.为什么用that we have achieved all that we expected.句子中为什么用that呢?可以用what不? 英语句子中什么时候要用is,应该放在什么词的前面还是后面 We all think it a pity that she didn’t come here中为什么没有is 这句话中 为什么 前面用 用that is ,而后面 又用 they All we need is enough money.这里的all后面是不是省略了that?