Learn German: Der Baum wird wieder grün. - The tree is turning green again.

The verb werden translates to "to become," "to get," or "to turn" when talking about a change in state. English often uses the -ing form like "is turning" or "is getting," but German uses werden. So wird grün means "is turning green."

I thought wird was used for the future tense ("will"). Is this talking about the future?

Not here! The verb werden is indeed used as a helping verb to build the future tense, but only when paired with a second verb at the end of the sentence. When it is the only verb in the sentence, as it is here, it acts as a main verb meaning "to become."

Why doesn't grün have an adjective ending, like grüner or grüne?

In German, adjectives only take endings when they are placed directly in front of a noun (like der grüne Baum). When an adjective comes after a state-changing verb like sein (to be) or werden (to become), it stays in its basic dictionary form without any endings.

What is the difference between Der Baum wird wieder grün and Der Baum ist wieder grün?