“认为……有用”的英语词组

consider...useful/consider...helpful.
用think也可以。

例句：
I consider it useful performing the experiment.
我认为做这试验是有用的。

When do you think we've going to get onto something useful?
你我认为我们什么时候开始干有用的事呢？

我认为这很有用 I think it helps

consider ......to be useful