Na het overgeven verwees de arts hem door.

Because Dutch often uses het + infinitive to turn a verb into a noun-like expression.

• overgeven = to vomit / to throw up
• het overgeven = the act of vomiting / throwing up

So na het overgeven literally means after the vomiting or more naturally after throwing up.

This structure is very common in Dutch:

• na het eten = after eating
• voor het slapen = before sleeping
• bij het koken = while cooking / when cooking

Without het, na overgeven would sound incomplete or unnatural in standard Dutch.

The first part, Na het overgeven, is placed at the beginning of the sentence. In Dutch main clauses, when something other than the subject comes first, the finite verb must still stay in the second position.

So the structure is:

• Na het overgeven = first element
• verwees = finite verb in second position
• de arts = subject
• hem door = rest of the sentence

This is called inversion.
If you started with the subject instead, you would get:

• De arts verwees hem door na het overgeven.

Both are grammatical, but the original sentence emphasizes the time phrase first.

Verwees is the simple past singular of verwijzen.

Forms:

• verwijzen = to refer
• verwees = referred
• verwezen = referred (past participle)

Examples:

• De arts verwijst hem door. = The doctor refers him onward.
• De arts verwees hem door. = The doctor referred him onward.
• De arts heeft hem doorverwezen. = The doctor has referred him onward.

So verwees is just the past tense form of that verb.

Here, door is part of the meaning to refer someone on / send someone on to another doctor or specialist.

Dutch can express this with doorverwijzen or with split forms in a sentence:

• doorverwijzen = to refer onward
• verwijst ... door
• verwees ... door

So in this sentence, verwees ... door belongs together.

This is related to how separable verbs work in Dutch:

• in the infinitive: doorverwijzen
• in a main clause: verwijst hem door, verwees hem door

So door is not optional here if you want that specific meaning.

In practical terms, it is functioning as doorverwijzen.

Dutch often splits separable verbs in main clauses:

• infinitive: doorverwijzen
• present: De arts verwijst hem door.
• past: De arts verwees hem door.

So although you see verwees and door separated, they belong together semantically.

You can think of it like this:

• dictionary form: doorverwijzen
• sentence form here: verwees ... door

Because hem is the object form of the pronoun, while hij is the subject form.

• hij = he
• hem = him

In this sentence:

• de arts is the subject
• hem is the person being referred

So Dutch uses hem, just as English uses him in The doctor referred him.

Yes. That is also correct, but it uses a different tense: the present perfect instead of the simple past.

Compare:

• Na het overgeven verwees de arts hem door.
  simple past; often used in narration and storytelling

• Na het overgeven heeft de arts hem doorverwezen.
  present perfect; very common in spoken Dutch

Both are grammatical. The choice depends on style, region, and context. In written narrative, verwees is very natural. In conversation, many speakers would prefer heeft ... doorverwezen.

No. Overgeven can have more than one meaning, which can confuse learners.

Common meanings include:

• to vomit / throw up
• to hand over / surrender / transfer

So context is very important.

In na het overgeven, the meaning is clearly after vomiting, not after handing something over.

This kind of ambiguity is normal in Dutch, just as many English verbs have multiple meanings.

Yes, grammatically that is close to what Dutch is doing, but in natural English you would usually say:

• after throwing up
• after vomiting

Dutch often uses het + infinitive where English prefers an -ing form.

So:

• na het eten = after eating
• na het overgeven = after throwing up

A literal translation can help you understand the grammar, but it usually sounds less natural in English.

Its position depends on the sentence structure, because it is the separable part of doorverwijzen.

Examples:

Main clause

• De arts verwijst hem door.
• De arts verwees hem door.

With another verb at the end

• De arts wil hem doorverwijzen.
• De arts heeft hem doorverwezen.

Subordinate clause

• ..., omdat de arts hem doorverwees.

So in a simple main clause, the prefix is usually separated and moved toward the end:

• verwees ... door

But in infinitives and participles, it stays attached:

• doorverwijzen
• doorverwezen

Yes, that is a good alternative.

Compare:

• Na het overgeven verwees de arts hem door.
• Nadat hij had overgegeven, verwees de arts hem door.

The first version is more compact and uses the noun-like infinitive construction.
The second version is a full clause with nadat + subject + verb.

The second version can be useful if you want to make the subject of overgeven explicit:

• nadat hij had overgegeven = after he had thrown up

So both are correct; the original is just shorter and very idiomatic.