Before I start, if you do not want spoilers and want to figure this out yourself, there are heavy hints as to how to translate what they are saying. When you ask a question they often tend to repeat what you said within their sentence. The sentences are also the same length letter for letter as their english counterparts. With that out of the way I found out how to translate what they are saying. You need to use a atbash cypher to translate what they are saying.
I wanted to rush this info out to help other people, but this guide is not complete and will be updated as I get more and better information. Here is what I have translated so far.
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Me: roof? home?
him: slnv? Blf ziv zhprmt zylfg slnv
him: Home? You are asking about home?
him: Nzbyv gsviv rh hgroo z dzb gl tvg yzxp
him: Maybe there is still a way to get back
him: R xznv gl erhrg z uirvmw, zmw, gsvm gsrh szkkvmvw
translated: I came to visit a friend, and, then this happened
him: Gsv hrgfzgrlm rh qfhg ufxpvw, ml lgsvi dliw uli rg
him: The situation is just ♥♥♥♥♥♥, no other word for it
him: Z kozmv Blf gsrmp gsvb hgroo uob
him: A plane You think they still fly
him: R hslfow gib gl urmw lfg hlnvdsviv
him: I should try to find out somewhere
him:Nzbyv gsviv rh hgroo z dzb gl tvg yzxp
him:Maybe there is still a way to get back
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*incomplete*
him: R dlmwvi ru gsv hznv gsrmt rh szkkvmrmt rm nb xlfmgib
him: I wonder if the same thing is happening in my country
him: Dszg z mrtsgnziv
him: What a nightmare
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when checking mouth
him: Nlfgs? …Nzbyv rg droo svok.
him: Mouth? …Maybe it will help.
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him: Nzb R zhp blf gl ivkvzg gsvg?
him: May I ask you to repeat thet?
him: R wlmg fmwvihgzmw. Dszg wl blf dzmg uiln nv
him: I don’t understand. What do you want from me?
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pointing at smile conversation
him: Ls, blf nvzm gsrh
him: Oh, you mean this
him: Gsvb nzmztvw gl gvoo nv gszg gizrmh ziv hgroo ifmmrmt! Xzm blf yvorvev rg?
him: They managed to tell me that trains are still running! Can you believe it?
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can someone drive you home?
him: R wl mlg fmwvihgzmw, uirvmw
him: I do not understand, friend
him: Glnliild R zn svzwrmt slnv! Li zg ovzhg gl gsv hgzgrlm.
him: Tomorrow I am heading home! Or at least to the station.
him: R’n ovzermt glmrtsg. Ybv!
him: I’m leaving tonight. Bye!
him: Bahbye!
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me: you mean the train?
him: I did not get that, sorry
him: Yfg glnliild R droo tl gl gsv hgzgrlm zmw hvv uli nbhvou
him: But tomorrow I will go to the station and see for myself
him: Nzbyv R droo tvg slnv zugvi zoo gsrh grnv
him: Maybe I will get home after all this time
him: GHUDLLUKK!