(The numbers are the paragraph)
1 - beholder? sounds a little weird, might work better with observer?
5 - "the purpose if this book" if -> of
6 - teach you writing code? -> teach you to write code?
programming languages
1 - "programmers need a language", "these languages"
abstraction
3 - languages provideS -> languages provide
3 - "other languages [โฆ] would not be recognised as programming" (??) (would any programming languages ever be recognised as "programming"?)
3 - "Today, we prefer not to use a low-level language" - sounds like everyone is using the same language? also feels a little odd with all the switching between "a" language and language/s/
4 - "but it will require five times blah" - sounds a bit to specific (yeah i'm sure it's just an example but it's not all that clear here), especieally since nothing else in the example is that specific ("few months", "a matter of days" etc)
4 - programmer time? i think programmers' time or A programmer's time could work better... but i dunno really. hm
7 - "Finding faults that program is made easy in high-level code" think you missed sumfin
do i need a language
"Programming as a hobby does not require a language. A language is only needed when you wish to actually communicate with the computer." wuh?
haskell
2 - fully-fledged -> full-fledged
haskell is unique
1 - "what makes me choose" -> "what made me choose" otherwise it kinda sounds like you're making a choice all the time, especially since you say "i have chosen" in the next paragraph
3 - "safe /for/ the changes"? also, "come in the /immediate/ future"? sounds... rushed. I'd say "near future" would sound better
"the future 20 years to come" also sounds kinda weird. a bit too over the top.
4 - minor issue with "loads of", a bit too... crude, to fit in with the rest of the book. "a lot of" might sound better.
features of haskell
6 - "which colour all the cars previously were" shouldn't colour be in plural, or did all the cars have the same colour? otherwise you could write "which colour each one of the cars previously were" or something
testing the interpreter
"Try typing 4 + 3 and press return" -> "then press" or "pressing"