Daai staproete is lank.

Daai means that or those. Unlike English, Afrikaans commonly uses the same form for both singular and plural.

So:

• daai man = that man
• daai mense = those people

In this sentence, it is most likely singular because staproete is singular: that hiking route/trail.

Also, daai is a very common spoken/informal form of daardie.

Yes. Staproete is singular.

That can confuse English speakers, because endings can look plural at first glance. But here the base noun is roete, which is already singular and means route.

So:

• roete = route
• roetes = routes
• staproete = hiking route / walking trail
• staproetes = hiking routes / walking trails

So in this sentence, staproete is singular.

Because Afrikaans usually writes compound nouns as one word.

Here:

• stap = walk
• roete = route

Together:

• staproete = walking route / hiking trail

This is very normal in Afrikaans. English often uses two words where Afrikaans prefers one compound word.

Is is the present-tense form used with wees in sentences like this, and it does not change the way English am / is / are does.

For example:

• Ek is = I am
• Jy is = you are
• Hy is = he is
• Hulle is = they are

So whether the subject is singular or plural, is stays the same.

This is a very common learner question.

In Afrikaans, some adjectives have one form when they come after the noun with is, and another form when they come before the noun.

For this word:

• Die staproete is lank. = The hiking trail is long.
• 'n lang staproete = a long hiking trail

So:

• after is: lank
• before a noun: lang

This is standard Afrikaans usage.

Because daai already fills that determiner slot, just like English that does.

Compare:

• Die staproete is lank. = The hiking trail is long.
• Daai staproete is lank. = That hiking trail is long.

So you do not add die after daai.

Yes. Daardie staproete is lank is perfectly correct.

The difference is mainly register:

• daai = common, everyday, informal
• daardie = more formal or more careful style

In normal speech, many speakers use daai very often.

Not really. In this simple main clause, the word order is very similar to English:

• Daai = that
• staproete = hiking route
• is = is
• lank = long

So the pattern is:

demonstrative + noun + is + adjective

That makes this sentence quite beginner-friendly in terms of structure.

A rough English-friendly guide:

• daai: roughly like dye
• staproete: roughly STAHP-roo-tuh
• lank: roughly lahngk

A few helpful notes:

• aa is a long vowel
• oe sounds like oo in food
• the r may sound stronger than in many English accents

These are only approximate English-style guides, but they are good enough to get started.