You are absolutely right, Emily. They are both correct, but there is a subtle difference in meaning: "he has gone" emphasises the action of departing, while "he is gone" emphasises the fact of his absence.

As Jacob has explained, "has gone" is present perfect, used to indicate an event in the recent past which impacts on the present. "Has gone" is the verb form, composed of the auxiliary verb "has" and the past participle "gone".  

"Is gone" is present simple: the verb is simply "is", while the "gone" is an adjective (or you could even argue for its being an adverb). It's like saying "He's here" or "He's there".

Why do we have these two forms? I don't know, but my hunch is that "He is gone" is a relic from an earlier time. The clue might lie in other European languages, which tend to have two different auxiliary verbs for perfect ("composed") tenses. In languages where this is the case, verbs of movement such as "go", "come" and "depart" ( also "die") take auxiliary verb "be" rather than "have'. For example, "Er ist gegangen" in German or "Il est parti" in French would translate literally as "He is gone".  Our forms such as "is gone"/"are gone"/"was gone" may go back to a time when our grammar was closer to German and possibly the same distinction between verbs of movement ( or change of state) and other actions also existed in English. I'm not sure about this, though - it's only a guess.

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Hi Emily,

I'm not a native English speaker, but I would like to give it a try:

He is gone: He died or his whereabouts is not known.

He has gone: He is somewhere but not here. (He has gone to the United States)

He has gone = present perfect simple, there is an emphasis on the fact that he has left to a place and implies to a certain extent that he is still there. The present perfect simple is used to talk about events in the recent past that still have an effect on the present.

He is gone = "he is" plus the adjective "gone". Here, the past participle, "gone" functions as an adjective. Here, the emphasis is that he is simply not here, but not that he left of is somewhere in particular, simply that he is not here. It is like saying, he is absent, or he is away, or he is missing. Notice that in the second example, "He is away", the word, "away" is an adverb, but functions as an adjective here. It is the same thing with the word "gone"

"He's" can be either "he is" or "he has", thus if it is stated this way, there is actually no way to tell other than from context if the person means" he is gone" or "he has gone"

I got this: https://english.stackexchange.com/questions/41453/she-is-gone-versus-she-has-gone

Also note. I am not a professional qualified teacher of English. But when I was taught English, before the days of over analysing the Language, or as they say "Language assessment" in teacher training colleges. I would have been taught to never use 'is gone' . But always "has gone'. Because "has" + "gone" = both the first part of the clause and the last part of the clause, are in the same tense. 

I know many are going to disagree with me, but teaching English today has become overly completed and unnecessary confusing to second language learners. Compared with fifty plus years ago.

If "he is gone" is generally considered to be a relic of the past. Then why not just tell the students. it is archaic. and today only used poetically to express someones death. 

YOU could swap "is gone" with "has gone" in this poem, the meaning would not be lost.

No wonder learners get confused when we discuss present and future tenses, for an ancient way of speaking.

http://www.funeralchoices.co.uk/Poems/he%20is%20gone.html

You can shed tears that he is gone
Or you can smile because he has lived 

 You can close your eyes and pray that he will come back 
Or you can open your eyes and see all that he has left 

--> MORE of the poem