Repartimos las cartas ahora.

Because Spanish often drops subject pronouns when the verb already makes the subject clear.

• Repartimos tells you the subject is we
• So nosotros repartimos las cartas ahora is grammatical, but nosotros is usually unnecessary unless you want emphasis or contrast

For example:

• Repartimos las cartas ahora. = We deal out the cards now.
• Nosotros repartimos las cartas ahora, no ellos. = We’re dealing the cards now, not them.

Repartimos can be either:

• present tense: we distribute / we deal out
• preterite: we distributed / we dealt out

For -ir verbs, the nosotros form is the same in the present and the preterite.

Here, ahora strongly suggests the present:

• Repartimos las cartas ahora. = We’re dealing out the cards now.

If you saw repartimos without context, you would need the surrounding words or situation to know which tense it is.

Because repartir is an -ir verb.

Its present-tense nosotros form ends in -imos:

• repartir → repartimos

Compare:

• hablar → hablamos
• comer → comemos
• repartir → repartimos

So repartemos is not the correct form.

Repartir means to distribute, to hand out, or in some contexts to deal out.

With las cartas, it often means:

• to deal the cards if you are talking about a card game

But in a broader context, it can also mean:

• to hand out the letters
• to distribute the cards
• to give things out among people

So the exact English translation depends on context, even though the basic idea is giving things out / dividing them among people.

It can mean either one.

• carta = letter
• carta can also mean card, depending on context

So las cartas could mean:

• the cards (playing cards, flashcards, etc.)
• the letters (mail)

If the meaning has already been shown to you, then context has already decided which one it is. But it is very normal for learners to notice that cartas is ambiguous by itself.

Spanish usually uses the definite article more often than English.

So Spanish commonly says:

• las cartas

where English might say either:

• the cards
• or just cards, depending on style and context

In Spanish, Repartimos cartas ahora is possible in some situations, but Repartimos las cartas ahora sounds more natural if you mean specific cards involved in the situation.

Yes, ahora can move around.

These are all possible:

• Repartimos las cartas ahora.
• Ahora repartimos las cartas.
• Las cartas las repartimos ahora. (more marked/emphatic)

The version with ahora at the end is very natural and can sound like:

• We’re dealing the cards now
• as opposed to earlier or later

Putting ahora first often gives it a little more emphasis:

• Ahora repartimos las cartas. = Now we deal the cards.

Not literally. Repartimos is an indicative form, not the usual let’s form.

If you want Let’s deal the cards now, Spanish would more naturally say:

• Repartamos las cartas ahora.
• Vamos a repartir las cartas ahora.

So:

• Repartimos las cartas ahora. = We deal / are dealing the cards now
• Repartamos las cartas ahora. = Let’s deal the cards now

This is a very common point of confusion for English speakers.

A common Latin American pronunciation is approximately:

• reh-par-TEE-mos

A few useful notes:

• The r in repartimos is a single tapped r, not the strong rolled rr
• The stress is on ti: re-par-TI-mos
• imos sounds like EE-mos

So the rhythm is:

• re-par-TI-mos

Not:

• RE-partimos
• or re-PAR-timos

Yes, repartir is a regular -ir verb.

Its present tense is:

• yo reparto
• tú repartes
• él/ella/usted reparte
• nosotros/nosotras repartimos
• ellos/ellas/ustedes reparten

Because it is regular, once you know standard -ir endings, this verb is straightforward to conjugate.