Ons ruil klere uit solank as die pasvorm gemaklik is.

Because uitruil is a separable verb in Afrikaans.

• The full verb is uitruil = to exchange / swap
• In a normal main clause, the verb splits:
  • Ons ruil klere uit
• In forms where the verb stays together, you may see:
  • om klere uit te ruil
  • uitgeruil in some perfect constructions

This is similar to separable verbs in Dutch and somewhat like English phrasal verbs, though the grammar is more fixed.

Ruil by itself means exchange, trade, or swap.
With uit, it becomes more explicitly exchange with each other or swap out.

In everyday use, ruil and uitruil can overlap a lot, but in your sentence ruil ... uit sounds natural for we exchange clothes.

So:

• ruil = trade / exchange
• ruil ... uit = exchange / swap

Klere means clothes and is normally treated as a plural or collective noun.

Like English clothes, it usually refers to clothing in general rather than one single item.

Examples:

• Ek koop klere = I buy clothes
• Sy dra mooi klere = She wears nice clothes

If you want to talk about one item, you would usually use a more specific word such as:

• hemp = shirt
• broek = trousers/pants
• rok = dress

Solank as means as long as.

It introduces a condition:

• Ons ruil klere uit solank as die pasvorm gemaklik is
• We exchange clothes as long as the fit is comfortable

You may also hear just solank used in many contexts with the same meaning:

• Solank die pasvorm gemaklik is ...

So solank as is correct and clear, but solank alone is also common.

Because solank as die pasvorm gemaklik is is a subordinate clause, and in Afrikaans the finite verb usually goes to the end of a subordinate clause.

Compare:

• Main clause: Die pasvorm is gemaklik
• Subordinate clause: ... solank as die pasvorm gemaklik is

This is one of the most important word-order patterns in Afrikaans.

Pasvorm means fit, especially the way clothing fits the body.

So here:

• die pasvorm = the fit

It is a common word when talking about clothes, shoes, tailoring, or sizing.

Related idea:

• Dit pas goed = It fits well

So pasvorm is the noun, while pas is often used as the verb.

Afrikaans often uses the definite article die in places where English might say the fit or sometimes just fit depending on style.

Here, die pasvorm means the fit in a general but specific sense: the fit of the clothes being discussed.

So:

• die pasvorm = the fit

Using die here is natural and expected.

No. Gemaklik stays the same here.

In this sentence, it is used as a predicate adjective after is:

• die pasvorm is gemaklik = the fit is comfortable

Afrikaans adjectives are much simpler than in many other languages. They do not change for gender or number the way adjectives do in some languages.

Sometimes yes, but the structure would usually be different.

For example:

• solank die klere gemaklik pas = as long as the clothes fit comfortably

That focuses more on the verb pas = fit.

Your original sentence uses the noun:

• die pasvorm is gemaklik = the fit is comfortable

Both are possible, but they are built differently.

Yes. It follows the usual Afrikaans main-clause pattern:

• Ons = subject
• ruil = finite verb
• klere = object
• uit = separated particle

Afrikaans main clauses usually place the finite verb in the second position. So this sentence has very normal word order.

In Afrikaans, ons can indeed mean both we and us, depending on the sentence.

Examples:

• Ons ruil klere uit = We exchange clothes
• Hulle sien ons = They see us

So the function is understood from word order and context.

By default, Ons ruil klere uit most naturally means we exchange clothes or we swap clothes, usually involving each other or within a group.

The exact situation depends on context, but it does not need an extra word to mean with each other. Afrikaans often leaves that understood if the meaning is clear.