Ons handig die vorm vandag in.

Because inhandig is a separable verb in Afrikaans.

The full verb is inhandig = to hand in / submit.
In a normal main clause, the conjugated part goes to the usual verb position, and the particle in moves to the end:

• Ons handig die vorm vandag in.

But when the verb is used as an infinitive, it usually stays together:

• Ons moet die vorm vandag inhandig.

So handig ... in is not two unrelated words here; it is one verb split into two parts.

Yes. Handig can exist by itself, but in this sentence it is part of the separable verb inhandig.

So here:

• handig ... in = submit / hand in

Do not read it as just handig plus a separate preposition. The meaning comes from the whole verb.

Not exactly.

In this sentence, in is a verb particle, not a normal preposition showing location. It belongs to inhandig.

So in:

• Ons handig die vorm vandag in.

in does not mean something like inside or into. It is just part of the verb meaning hand in / submit.

Because Afrikaans verbs usually do not change much according to the subject.

In English, we say:

• I submit
• he submits
• we submit

In Afrikaans, the verb is usually the same for all persons in the present tense:

• Ek handig in
• Jy handig in
• Ons handig in
• Hulle handig in

That is one reason Afrikaans verb grammar is often simpler than English verb grammar.

Die means the.

In Afrikaans, die is the normal definite article for both singular and plural nouns:

• die vorm = the form
• die vorms = the forms

Afrikaans does not change die for gender or case the way some other languages do.

Afrikaans main clauses usually follow the verb-second rule.

That means the finite verb normally comes in the second position of the clause:

• Ons | handig | die vorm vandag in

Here:

• Ons is first
• handig is second
• the rest follows after that

Because inhandig is separable, the particle in goes to the end.

So the sentence structure is very typical Afrikaans:

• subject first
• finite verb second
• other information after that
• separable particle at the end

Yes. Afrikaans allows some flexibility, especially with adverbs like vandag.

You can also say:

• Ons handig vandag die vorm in.
• Vandag handig ons die vorm in.

These all mean roughly the same thing, but the emphasis changes slightly.

• Ons handig die vorm vandag in. → neutral, with today later in the sentence
• Vandag handig ons die vorm in. → stronger focus on today

If vandag comes first, the verb must still stay in second position:

• Vandag handig ons ... not
• Vandag ons handig ...

In Afrikaans, ons means both we and us, depending on its role in the sentence.

Examples:

• Ons handig die vorm in. = We submit the form.
• Hulle sien ons. = They see us.

So Afrikaans does not distinguish between we and us in form. The sentence structure tells you which meaning it has.

Afrikaans usually uses double negation.

So:

• Ons handig die vorm vandag in. becomes
• Ons handig nie die vorm vandag in nie.

You normally place:

• the first nie after the finite verb
• the second nie at the end of the clause

That double nie ... nie pattern is very important in Afrikaans.

In a yes/no question, Afrikaans typically puts the finite verb first:

• Handig ons die vorm vandag in?

Because the verb is part of a separable verb, the particle in still stays at the end.

So the statement:

• Ons handig die vorm vandag in.

becomes the question:

• Handig ons die vorm vandag in?

Then the main verb usually goes to the end in its infinitive form, and the separable verb is written together:

• Ons moet die vorm vandag inhandig.

Notice the difference:

Main clause with finite inhandig:

• Ons handig die vorm vandag in.

With a modal:

• Ons moet die vorm vandag inhandig.

So when it is not the finite verb, it is usually inhandig, not handig ... in.

Yes. Vorm is closely related in meaning and is often easy for English speakers to recognize in context.

In this sentence, die vorm means the form in the document/paperwork sense.

It is a useful example of how Afrikaans often has vocabulary that looks familiar to English speakers, even if the spelling is slightly different.