非正式的用法有很多，用不着，希望没有，做什么用英语怎么说呢？优朗英语口语培训的蓝老师做了个小整理，希望对要学英语的你有所帮助。

can do without 是用不着，希望没有的非正式说法，表示不想要或摆脱某事物。

例句：

I really can do without Peter's constant interruptions .

我真不想让彼得不停地打断我。

We can do without Angela telling us any more of her funny stories .

我们不想听安杰拉讲她的滑稽故事了。

I'm sure Daddy can do without your helpful comments when he's trying to mend the computer .

我敢肯定，爸爸修理电脑时不想听到你再旁边乱给意见。

情景模拟：

The Smith family have had a lot of bad luck this year .

Mr Smith lost his job when the factory closed down .

Mrs Smith fell off her bicycle and broke her arm .

So they could really do without the children being ill over Christmas . 

be up to是做什么的非正式用语，可用来询问别人正在做什么事。它所跟的词往往是一些人不好的举动，比如be up to mischief (调皮捣蛋)或be up to no good (做坏事) 。

例句：

‘Hello , John ,what have you be up to since I saw you last ?’‘Morning , Brian. I've got a new job, didn't I tell you? ’

“嗨，约翰，自从我们上次碰面后你一直在忙些什么啊？”“早安，布莱恩，我没告诉你吗？我找到了一份新工作。”

That man's been standing there all morning watching the house next door . I'm sure he's up to no good .

那个人整个上午一直站在那儿顶着隔壁的房子，我敢肯定他一定心怀不轨。

NOTES!

有时be up to 也可写成 get up to , 如 get up to mischief  (调皮捣蛋)

Are you sure the children won't get up to mischief if we leave them in the house on their own ?

如果我们将孩子独自留在家中，你敢肯定他们不会调皮捣蛋吗？

情景模拟：

It's too quiet upstairs . I'm sure the girls are up to something .

I'll go and have a look .

All right , what are you girls up to then ?

Martha , you'd better come and see this !