It's called "consonant softening" (ünsüz yumuşaması) it's something even Turkish students learn at school! :) Basically for words ending in "p, ç, t, k" if a vowel follows these letters turn into "b, c, d, ğ" Since "et-" is the noun, and iyoruz are the suffix combination indicating time and person "t" turns into a "d".

"Can" is expressed with "abilmek, ebilmek" suffix in Turkish. "I can do it!" "Bunu yapabilirim!" (Here it's abilmek because of vowel harmony) "I can come with you." "Seninle gelebilirim." (Here, it's ebilmek again vowel harmony.) Must and have to are the same things in Turkish. It's expressed with "-meli, -malı" suffixes. "You have to come." "Gelmek zorundasın." "You must stop." "(Sen) durmalısın." Also you can use "zorundayım" it's basically "verb + zorundayım" "I have to sleep." "Uyumak zorundayım." If is "eğer" "If you're going to visit us, bring your friend too." "Eğer bizi ziyaret edeceksen, arkadaşını da getir." I hope these help, have a nice day. :)

It means, whatever they're talking about isn't related to something else Dorothy thinks it is. Let me give an example too, just in case. "I can't believe you stopped talking to me to become friends with Dorothy." "It has nothing to do with her."

It can be used as an adverb or an adjective, depending on the context but in the example you give it's an adjective in my opinion. Because it doesn't define the verb, it's just a rephrased version of "most likely bacteria form to develop on a planet" so it is again, related to a noun. We don't say that "happy" is an adverb when we say "She's happy to be here." or say it defines the verb "to be". I hope it helps, have a nice day.

I can suggest memrise and duolingo by the way they both have Turkish courses that is made by the them, not the members so especially Memrise's courses are pretty good

They can be used interchangeably! But not always. Kendi is the most different one because it's not limited to "first person singular". "He did it himself." is also "O bunu kendi yaptı." so kendi is basically xself for singular subjects. For plural subjects that would be "kendileri" So since it means "xself" we can't use it when we want to indicate singularity. "Come alone!" could be translated as "Yalnız gel!" or "Tek gel" but not as "Kendin gel" in fact "kendine gelmek" is used as a phrase meaning "come to your senses" or "regain consciousness." Sorry if it's off topic! :) For the example you've given "tek başıma" is the most natural one and "yalnız" can't be used. If it's not already enough confusion for you, I must add that also "kendi kendime" can be used. So to sum it up, you can express it in two ways. "Kendi kendime öğrendim." or "Tek başıma öğrendim."

There's a subtle difference. You can say "It's cold in here." If you're in a room, a building, a classroom etc. But you can't say it if you're outside. And the same thing applies to "I'm in here." I can say this only if I'm in a room and for an example letting my friend know I'm there. I can't say "I'm in here" if I'm waiting to meet with the same friend at the town square and trying to make them recognize me by shouting. Same applies to every example in fact. "Why are you here?" "Why are you in here?" "It's dark here." "It's dark in here." and so on.

Shutter normally means "the outside covers of a window" also as a verb it means "to close down (a store, company etc)" but it means nothing in "Shutter Island" It's translated as "Island of Dungeon" in Turkish for an example so as you can see most of the time many languages don't stay true to the original. :)