Learn Romanian: El lucrează cu un unchi al lui. - He works with an uncle of his.

In Romanian, when a noun has an indefinite article (like un unchi - an uncle), we must use a linking word called the possessive article (al, a, ai, or ale) to connect it to the owner. This is similar to saying "an uncle of his" in English.

Why is the linking article al and not a, ai, or ale?

The linking article always matches the gender and number of the thing being owned, not the owner. Since unchi (uncle) is masculine and singular, we use al. If it were a feminine noun like o mătușă (an aunt), we would use a instead.

Is lui the only way to say "his" here?

lui literally means "of him" and is the standard way to show a male owns something. Because it refers strictly to the owner (him), the word lui itself doesn't change regardless of what he owns.

The dictionary form for "to work" is a lucra. Why does it become lucrează here?

A lucra is part of a very common group of verbs ending in -a that add an extra sound (-ez or -ează) to their stem in the present tense. For "he works" or "she works", the form is always el/ea lucrează.