Building on Joe's answer, grammatically, the "hurt" in
"Are you hurt?"
is a past participle of the verb "to hurt", used formally in the transitive sense (= to cause pain or injury to someone), but combined here with the auxiliary "be" to form passive voice.
On the other hand, the "hurt" in
"Do you hurt?"
is just the bare infinitive of the intransitive verb "to hurt" (= to be in pain), used with the auxiliary "do" to form a present tense interrogative.
The verb "hurt" just happens to be irregular, such that its past participle looks identical to the bare infinitive. The grammar becomes clearer if we replace it with more regular verbs like, say, "injure" and "ache" (which also have the advantage that "injure" is always a transitive verb, whereas "ache" is generally intransitive):
"Are you injured?" (be + past participle)
"Do you ache?" (do + bare infinitive)
And yes, the past participle of English verbs behaves grammatically like an adjective, so it's also legitimate to analyze the first sentence as "Are you <adjective>?"
Indeed, several English adjectives (including, notably, the word "past" itself) started out as past participles of verbs, but later lost the connection with the original verb. This can happen because the verb itself has otherwise fallen out of use (for example, "crook" is rarely used as a verb any more, but "crooked" is still a perfectly good adjective) or because the original irregular participle has been replaced by a more regular one (as in "past" vs. "passed", or "wrought" vs. "worked").
Even when both the verb and its participle remain in common use, it's not unusual for the participle to acquire secondary meanings or connotations that don't directly map back to the verb. For example, off the top of my head, the adjective "baked", while clearly a regular past participle of the verb "bake", also has the slang meaning "high on marijuana" that doesn't correspond with any meaning of the original verb.
Arguably, this is somewhat true of "hurt", too — even though it's originally a past participle of a transitive verb, in common usage it doesn't really carry any connotation of there being an active agent that caused the injury. That is, you can be hurt (adjective = past participle) even if nobody has hurt (past tense) you.
Use "once I was back home" or "once I got back home.
- Once vs when...
Once and when could both be used here generally speaking. However, using "once" here means that something is happening quickly after you arrive home. It's a little more dramatic and seems to match the tone of your story.
Using "when" also implies an order of events, but is a little more relaxed.
"Once" also makes it sound like it was a little more difficult to get back home.
- Adding "I was" or "I got" to the sentence.
"When back home" is understandable in context, but "when I got back home" is clearer to the reader. It also proves to the reader that you did, in fact, go home. In some contexts, "when back home" could be read as "when I get back home". So the reader may think you are talking about the future instead of the present.
Best Answer
Yes.
That is a grammatically correct phrase. Whether or not you should use it depends on your intended meaning. The phrase "Call me when you are available to talk" implies that you want someone to call you once their situation allows it. The wording sounds a bit formal, but it would be acceptable in just about any situation.
If you want to express that they need to call you as soon as possible, you would say just that: "Call me as soon as possible" or "Call me as soon as you can".
If your request is not urgent, then you could say "Call me whenever you get the chance" or "Call me whenever you can".
It's also worth noting that if you mean to request that someone return your call, you would usually say "Call me back".