使え

使え

"Use it" or "can be used."

Here, '使えます' is used in a declarative form to express the action of the tool being usable.

この道具は簡単に使えますよ。

This tool can be easily used.

Here, '使え' is a command form in reported speech, indicating an instruction to use something.

彼女にそれを使えと言われた。

She told me to use it.

Here, '使えない' is the negative form, expressing the inability to use something due to circumstances.

電波が悪くて電話が使えない。

The signal is bad and the phone cannot be used.