Plain form
oblige

Third-person singular
obliges

Past tense
obliged

Past participle
obliged

Present participle
obliging

(transitive); (usually passive) If you are obliged to do something, a law, rule, or situation forces you to do it.
She felt obliged to make conversation before leaving.
(transitive & intransitive) If you oblige someone, you do something that they want you to do.
We asked three experts they obliged with very clear answers.
(formal) If you tell someone that you'd be obliged if they did something, you're asking them to do it.
If you say, "much obliged", you are thanking somebody for something.

Verb