Learn English – Does the verb “reduce” have an adjective form meaning “can be reduced”

Translate is a verb. In your example, it is acting as an adjective. For example:

"He translated the book." - verb
"This is the translated edition." - adjective

Thought-provoking question!

I think we need to look at the sentence structure or else it'll be difficult to find it out. While transitive verbs make our task easy as they'd have a direct object following them. the problem occurs when the verb is intransitive.

But then, if you use 'intransitive' verbs, the sentence won't look complete without explaining the verb. For instance, 'break' is transitive and intransitive both (just like 'clean'); now you'll have to talk about the verb further in order to make the sentence complete.

He has broken - won't work

The moment you add '....his glass', we can make out that it is used as a verb.

The adjective pattern will be different than the 'verb pattern' in those sentences with PP.

In English, a 'single word' on its own may stand ambiguous. That's why we say, context is important.

[But let natives come with their take on this].