I have a somewhat basic and embarrassing question to ask. I sometimes get confused as to determining what is an adjective and what's a verb. Clearly, adjectives modify nouns while verbs are actions. However, some words just don't seem to fit neatly in the aformentioned classifications. For example, the word traumatized. In the dictionary, traumatized is listed as a verb and not also an an adjective. How is that possible? Can't one cleary describe someone as traumatized and thus use this word as an adjective?

Is their a foolproof way (i.e. a question I can ask myself) to accurately discern what is an adjective and a verb?

Many kind thanks for anyone who replies to this post.

With your example, traumatized is a past participle used as an adjective. It's origin is a verb but many view it as an adjective, but there is another camp which considers this use passive.

This usage is very common. i.e. She was very confused, interested, exhausted etc... (by something).
Students: Are you brave enough to let our tutors analyse your pronunciation?
Dear Goodman,
I would begrateful if you could write some links for the sources to prove any of the abovementioned points of view.
Irene Emotion: thinking
 CalifJim's reply was promoted to an answer.