Die valmat lê onder die klimwand.

In Afrikaans, die is the definite article, meaning the.

So in Die valmat lê onder die klimwand, both nouns are definite:

• die valmat = the crash mat
• die klimwand = the climbing wall

Unlike languages such as German, Afrikaans does not change the word for the according to gender or case. So die is used very widely.

Valmat is a compound noun, which is very common in Afrikaans.

It is made from:

• val = fall
• mat = mat

So valmat literally means fall-mat, i.e. a crash mat or safety mat.

Afrikaans often builds nouns this way, just like English can do with words such as bedroom, football, or toothbrush.

Lê means lies / is lying.

Afrikaans often prefers a position verb instead of just is when talking about where something is. That means the language often chooses a verb that shows the object’s position:

• lê = lie
• staan = stand
• sit = sit

A mat is thought of as something that lies flat, so lê is the natural choice.

So:

• Die valmat lê onder die klimwand = The crash mat lies/is lying under the climbing wall

Using is would usually sound less natural here.

These are very important location verbs in Afrikaans:

• lê: used for things that are lying flat or spread out
  
  • Die boek lê op die tafel.
• staan: used for things that stand upright
  
  • Die bottel staan op die tafel.
• sit: used for things sitting in a place, often enclosed, attached, or positioned somewhere
  
  • Die sleutel sit in die deur.

In your sentence, a crash mat is flat on the ground, so lê makes sense.

Onder means under.

It is a preposition, and it introduces the phrase die klimwand.

So:

• onder die klimwand = under the climbing wall

A helpful point for English speakers: Afrikaans does not change the article after onder. You still just say die. There is no extra case marking like in German.

Klimwand is also a compound noun:

• klim = climb
• wand = wall

So it literally means climb-wall, or climbing wall.

This is a very typical Afrikaans way of forming vocabulary.

Yes, in this simple sentence the word order is very similar to English:

• Die valmat = subject
• lê = verb
• onder die klimwand = prepositional phrase showing location

So the structure is:

Subject + Verb + Place

That makes this sentence quite friendly for English speakers.

The ê shows a different vowel quality from a plain e. In practice, learners should notice that lê is pronounced differently from an ordinary short e and should be learned as its own word sound.

A simple learner-friendly approach is:

• say lê as one syllable
• keep the vowel clear and a bit longer/opener than a plain e

The accent mark matters, so it is good to learn the spelling and pronunciation together.

It would probably be understood, but Die valmat lê onder die klimwand is more natural Afrikaans.

That is because Afrikaans often prefers a posture/location verb like lê when describing where an object is.

So:

• Die valmat lê onder die klimwand = more idiomatic
• Die valmat is onder die klimwand = understandable, but less natural

No, not in the way that languages like German or Dutch do.

For a learner, this means a big simplification:

• you do not have to memorize whether valmat or klimwand is masculine, feminine, or neuter
• the article stays die here regardless

That is one reason Afrikaans grammar often feels more straightforward to English speakers.