"He becomes a father soon" sounds very odd to me. In English we use the simple present to talk about habitual action or a sudden change in a story and the present progressive to talk about the near future. I could only imagine saying "he becomes a father" in the context of a story ("Richard holds his breath as his wife pushes one last time, and as the screaming little girl emerges into the world he becomes a father," or something.)
To translate this sentence, there seem to be a number of options that sound good: "He is becoming a father soon" or "Soon he is becoming a father" are OK but honestly still a little unnatural. "Soon he will become a father" sounds better. "He'll be a father soon" sounds good too.
I just get annoyed with the "implied" future tense, such as "will become a father" when I am still struggling with the simple usage of "becoming a father". why not be just a little less hard-nosed about that? I am still working mostly present tense here! In the other languages (Spanish and French, at least), they cut you a little slack on the nuances. It is not that I am obsessing about the points (hearts), but rather not really knowing when the judges are going to ding me on it!
The article ('a') is required in English, even though it is apparently not needed in Dutch.
You could say, "He will soon become Father" if someone were about to transform themselves into your father in some sense. But that is not what the Dutch sentence is about. It is about someone who is about to have a child. In English we say they are becoming "a father."
- worden = to become
- hij wordt = he becomes
However, it is still standard in Dutch (as in all Germanic languages except English, since they didn't used to have any future tense) to use ordinary present when futurity is clear from context. Therefore also:
- hij wordt = he will become
I guess your train of thought was more like this:
- worden (auxiliary for future tense) = will (auxiliary for future tense)
- hij wordt [isn't there a full verb missing?] = he will [let's put be here so it's grammatical]
But now the following should be clear:
- Hij wordt binnenkort vader. = He will soon become a father. (Literally: He becomes (a) father soon.)
- Hij wordt binnenkort vader zijn. = He will soon be a father.
It is not proper English word order. The ultimate reason for this is that it says that he will be something, and that something will be "soon a father". This is almost never what people mean. Correct options:
- Soon he will be a father.
- He soon will be a father. [unusual]
- He will soon be a father.
- He will be a father soon.