Beide stappers is moeg.

In Afrikaans, the verb is is used for all persons and numbers in the present tense of to be.

So you get:

• Ek is — I am
• Jy is — you are
• Hy is — he is
• Ons is — we are
• Hulle is — they are

So in Beide stappers is moeg, is is completely correct even though stappers is plural.

Beide means both.

In this sentence, it is used before a plural noun:

• beide stappers = both walkers / both hikers

It tells you that the statement applies to the two walkers together.

Stappers is the plural of stapper.

• stapper = walker, hiker
• stappers = walkers, hikers

It comes from the verb stap, which means to walk / to step.

Depending on context, stapper can sound like walker or hiker in English.

The singular is stapper and the plural is made by adding -s:

• stapper → stappers

This is a very common plural pattern in Afrikaans.

Afrikaans often leaves out die when a word like beide already works as the determiner.

So:

• Beide stappers = both walkers

This works much like English, where we say both walkers, not normally the both walkers.

Yes. Albei also means both, and in many situations it is interchangeable with beide.

So these are both possible:

• Beide stappers is moeg
• Albei stappers is moeg

In everyday speech, albei is often very common. Beide can sound a little more formal or written, though both are normal Afrikaans.

Because moeg is being used after the verb is.

In Afrikaans, adjectives used after a linking verb usually stay in their basic form:

• Die man is moeg
• Die vrou is moeg
• Die kinders is moeg

So in Beide stappers is moeg, moeg does not change.

If the adjective comes before the noun, it may change form instead:

• moeë stappers = tired walkers

The sentence you would want in Afrikaans is:

• Die stappers is beide moeg

That is also correct, but it is slightly different in structure.

Compare:

• Beide stappers is moeg = Both walkers are tired.
• Die stappers is beide moeg = The walkers are both tired.

The meaning is very similar, but the emphasis and structure differ a little.

A rough English-friendly guide is:

BAY-duh STAH-pers is moogh

A few notes:

• ei in beide sounds roughly like the vowel in day
• a in stappers is short, like in cup for many speakers
• g in moeg is the guttural Afrikaans g/ch sound, made at the back of the throat

Pronunciation varies somewhat by accent, but that approximation is a useful start.

Yes. This is standard word order for a simple statement:

• Beide stappers — subject
• is — verb
• moeg — complement/adjective

So the pattern is:

Subject + verb + adjective

That is one of the most basic and common sentence patterns in Afrikaans.

Yes. Beide means both, so it refers specifically to two people or things.

If there are more than two, Afrikaans would use other words, such as:

• al die stappers = all the walkers
• al drie stappers = all three walkers

So beide stappers tells you there are two walkers, and both of them are tired.