useful

有用的:

It's quite a handy little tool.

这件小工具非常有用。

It's very handy having a light above your desk.

书桌上方有盏灯很有用。

Take your swimming trunks with you – they might come in handy (=be useful) .

带上你的游泳裤，可能会派上用场的。

[informal] near and easy to reach

手边的，附近的:

I always keep my gun handy just in case.

我总是随身带着枪以防万一。

Do you have a piece of paper handy ?

你手边有纸吗？

The house was in Drury Lane, very handy for the theatre.

那房子在德鲁里街，离剧院很近。

good at using something, especially a tool

手巧的，灵活的:

He's very handy with a screwdriver.

他善于修修弄弄。