V得了 / V不了【de liǎo / bu liǎo】

不了 after a verb says the action can't happen, and 得了 that it can. 了 in this pattern is read liǎo, the old verb "finish, manage", not le.

Can't manage, or can't get through it all

The first meaning is "can't manage it": something gets in the way.

The second, with verbs of using something up – eating, drinking, spending – is "can't finish it all".

V不了 or 不能

不能 also covers rules and permission; V不了 is only about whether something is possible. 我不能去 can mean you aren't allowed. 我去不了 says circumstances stop you.

"Won't" with a handful of verbs

With 错, 忘 and 少, 不了 is a confident prediction: 错不了 "can't be wrong", 忘不了 "will never forget", 少不了 "can't do without".

Word order

不 goes between the verb and 了, never in front of the verb. An object follows 不了 or moves to the front as the topic.

• × 我不去得了 → 我去不了
• × 我吃了不这么多 → 这么多我吃不了

The positive 得了 turns up mostly in questions and in the answers to them; a plain statement usually takes 能.