Verb usage at times is diversify and confusing at times.
Earlier today, my superior at my working place asked me this: "Has he back?" Two days earlier he asked the same question but different a bit, he said, "Is he back?"
Please, expatiate on those two sentences.
"Has he back" doesn't have a clear meaning to me. If someone said it to me I would say "What?" and ask for clarification.
"Is he back" is easier, and is perfectly idiomatic. It just means "Is he back [in this place, after having been somewhere else]." If that's what your superior meant, then that's a better way to say it.
You can use "has" if you also use other words, like "Has he come back"; this is just using present perfect tense.