be able to
能够（做某事）

Be able to 比 can 更加正式一些。 
Be 跟着主语变化，如 I'm able to，you're able to，he's able to，she's able to...

I am able to attend the meeting.
I'm able to attend the meeting.
我能够参加会议。
attend the meeting 参加会议
attend 参加，出席，到场

You are able to leave the country without a passport.
You're able to leave the country without a passport.
你可以在没有护照的情况下离开这个国家。
without 没有，无，缺少

He is able to drive a car.
他会开车。
He's able to drive a car.

She is able to read without glasses.
She's able to read without glasses.
她不戴眼镜就能看书。

We are able to buy a new house.
We're able to buy a new house.
我们能买个新房子。

They are able to walk very far.
They're able to walk very far.
他们能走很远。