Ons draai die kleppie op die lekband los.

Because losdraai is a separable verb in Afrikaans.

Its basic form is losdraai = to loosen / unscrew by turning. But in a normal main clause, the verb splits:

• Ons draai ... los

The finite verb draai goes near the beginning of the sentence, and the particle los moves to the end.

This is very common in Afrikaans:

• oopmaak → Hy maak die deur oop
• afsit → Sy sit die lig af
• losdraai → Ons draai die kleppie ... los

So los is at the end because that is how separable verbs behave in main clauses.

Yes, literally it is something like turn loose, but idiomatically it means loosen, unscrew, or undo by turning.

So in this sentence, draai ... los is not just the ordinary verb draai (turn) plus a random extra word. The two parts work together as one meaning unit:

• draai = turn
• los = loose / free
• losdraai = loosen by turning

A native English speaker can think of it a bit like screw off, unscrew, or loosen depending on context.

Kleppie is the diminutive form of klep.

So:

• klep = valve
• kleppie = little valve / small valve

In Afrikaans, diminutives are extremely common. They do not always sound as strongly cute or tiny as they might in English. Often they are just the normal, natural way to refer to a small object.

The spelling changes because of Afrikaans diminutive formation:

• klep → kleppie

The extra p helps keep the short vowel sound.

Not necessarily.

Grammatically, it is a diminutive, so little valve is the most literal translation. But in natural English, you may often just say valve if the smallness is not important.

In other words:

• literal: little valve
• natural in context: valve

Afrikaans uses diminutives much more freely than English does, so learners should not always force little into the translation.

It means on the flat/leaking tyre.

Breakdown:

• op = on
• die = the
• lekband = leaking tyre / flat tyre

Here op shows location: the valve is on the tyre.

Also, note that band in Afrikaans can mean tyre. So lekband is not a band in the English sense of a strip or group; it is a kind of tyre-related word.

Because Afrikaans normally writes compound nouns as one word.

So:

• lek = leak
• band = tyre
• lekband = leaking tyre / flat tyre

This is very typical of both Afrikaans and Dutch-style word formation. English often uses two words where Afrikaans uses one.

Other examples of the same idea are:

• motorband = car tyre
• huisdeur = house door / front door
• skooltas = school bag

So lekband as one word is completely normal Afrikaans spelling.

Because die is simply the definite article the, and Afrikaans uses it before each definite noun here:

• die kleppie = the valve
• die lekband = the flat tyre

A useful thing for English speakers: Afrikaans die does not change for gender or number.

So the same word die can mean:

• the (singular)
• the (plural)
• masculine / feminine / neuter — all the same form

That makes articles much simpler than in many other languages.

In Afrikaans, verbs usually do not change form according to the subject in the present tense.

So you get:

• Ek draai
• Jy draai
• Hy draai
• Ons draai
• Hulle draai

The verb stays the same.

This is one reason Afrikaans grammar often feels simpler than English verb conjugation. You do not need different present-tense endings like I turn / he turns.

Because Afrikaans often uses the simple present where English prefers the present progressive.

So:

• Ons draai die kleppie op die lekband los
  can mean
• We loosen the valve on the flat tyre
  or, in context,
• We are loosening the valve on the flat tyre

Afrikaans usually does not need a separate form for am/is/are ... -ing in everyday sentences.

If you really want to stress that the action is in progress, Afrikaans can use a construction like:

• Ons is besig om die kleppie ... los te draai

But that is more explicit and not always necessary.

Not in a normal main clause.

In a main clause, the separable verb splits:

• correct: Ons draai die kleppie op die lekband los

Using losdraai as one unbroken word in that position would sound wrong.

You normally see the joined form losdraai in places like:

• dictionary form: om los te draai / losdraai
• infinitive-like use
• some compound or dependent structures

But in an ordinary statement, Afrikaans wants:

• draai near the front
• los at the end

So the split form is the expected one here.