language, languish

Language or language means the body of words and their grammatical rules, common to a set of people--
Travel is easier if you can speak the language of the country you're visiting.
He wants to study a foreign language, but he's not sure which one.

Language may also mean a style or type of communication or verbal expression--
His use of language is distinctive; I'd recognize it without a signature.
Some scientists believe that the bees have a language of their own.
Watch your language!

Languish or languish means to become weak or to droop, particularly from neglect, literally or figuratively--
She's afraid the garden will languish if she doesn't take care of it herself.
Don't let them languish for want of attention; go and talk to them.

Now that you know that, you can say--
"He was unable to speak the language, and so he began to languish, socially, for want of someone to talk to."