Is this the normal way of making statements in Turkish? I mean this in the sense that in English you'd normally say "I am reading you a book", I think. Although "I read you a book" is correct, it sounds very technical, but I've noticed how in Turkish the gist of a sentence is often given more plainly compared to English, so I was just wondering :-)
no, Turkish uses present continuous much more than English. We are teaching different tenses here, so we have to build sentences using all of them. Actually the English tree in duolingo is using the present simple all over the tree and it is really annoying because it is full of unnatural sentences. We started following it in the very beginning of the tree so there we have some sentences in simple present. However we start teaching present continuous very early on and use it most of the time.
Also keep in mind that the sentences need to be short, not providing much context. ""I read you a book every night" is a very natural sentence in English, so is "Ben size her gece bir kitap okurum." in Turkish.
"I am reading you a book" would use the present continuous in Turkish, so ben size bir kitap okuyorum. The difficulty is that the difference we perceive in English between "I read" vs. "I am reading" doesn't perfectly map onto the difference between present continuous, which Turkish seems to use much more than we would be happy with in English, and aorist, but there's a good explanation in the Tips Notes.
EDIT I defer to Selcen!
No we can't because we use them according to whether the pronoun is singular/informal or plural/formal.
Sen - you (singular) eg. Let's say if you want your brother to eat instead of watching TV, you will say "You eat!" ( sen yersin! )
Siz - you (plural) eg. You all eat! (Siz yersiniz!)
Sana - for you / to you (singular) eg. I read you a book ( equivalent to "I read a book for you" ) ( Ben sana bir kitap okurum )
Size - for all of you / to all of you (plural) eg. I read you a book (equivalent to "I read a book for you all" (in plural case)) ( Ben size bir kitap okurum ).
I hope you will find it helpful :)