"Hij wordt vader."
Translation:He is becoming a father.
Ah, those hints are confusing, I will fix them.
"Wordt" can sometimes be translated as "is" or "is being", but only in a special construction (the passive voice). In this sentence, that translation is not applicable, the subject is not yet a father.
Duolingo decided to put "is" on top of the list of hints, since the 'best translation' contains the words "is becoming". It's an annoying technical glitch.
You would specify that he is becoming just like his father, or that he is just like his father.
- Hij wordt net (zo)als zijn vader - He is becoming just like his father
- Hij is net zijn vader - He is just like his father.
- Hij lijkt steeds meer op zijn vader - He looks more and more like his father
guess the sentence: hij is vader aan het worden, would be a correct sentence, though it would imply that he is becomming father right at this moment. so like his wife is giving birth right now. though, it is not a sentence I would normally use.
hij wordt vader, means his wife is pregnant (or whoever else he got pregnant)