He read a book written in English.
Could it also be “ספר (ש)כתוב באנגלית”?
This verb refers to the event of being written. For the state of having been written, the adjective כָּתוּב (katúv, “written”) is used.
The nuance feels shaky both in English and Hebrew to me, but כתוב seems to be more “an English-language book” or “a book written in English” (i.e. the focus is on the book and we just add the language it was written in as a descriptor) vs נכתב “a book that was/has been written in English” (i.e. the focus is on the action of writing and how it was done; a clearer example would be “a book that was written with a fountain pen”, you wouldn’t say “a fountain-pen-written book”). Basically nif’al is used to describe an action (that results in a state), while katul (a mishkal, not a binyan) is just an adjective (describing a state), adding information about something to a noun.
In this case it kinda feels (at least the way I’d imagine a situation where I’d use this sentence) like כתוב would fit more, as the main action is reading of a book that’s in English, not the action of the book having been written. An example where a book would be נגתב in English would be if I was listing books I wrote and went “this one’s written in Hebrew, that one’s written in English” (or more like “this one I wrote in Hebrew, that one in English”).
I imagine both options are ultimately fine (just like “a book written in English” and “a book that has been written in English” ultimately means the same, with maybe some extra nuance), but if someone can give me a deeper explanation or if there’s a reason it’s נכתב here rather than כתוב (very likely just to show the form, considering the set), I’d be curious.