Haar serp is nie so lank soos myne nie, maar dit is sagter.

Afrikaans often uses a double negative structure.

In this sentence, the pattern is:

nie so ... soos ... nie = not as ... as ...

So:

• nie after the verb introduces the negation
• the final nie closes it

That is completely normal Afrikaans grammar.

Examples:

• Hy is nie so oud soos ek nie. = He is not as old as I am.
• Dit is nie maklik nie. = It is not easy.

So the two nie's are not two separate negatives in the English sense. They are one standard Afrikaans negative frame.

This is the Afrikaans way to say not as ... as.

The pattern is:

nie so + adjective + soos + noun/pronoun + nie

In your sentence:

• nie so lank soos myne nie
• literally: not so long as mine
• natural English: not as long as mine

More examples:

• Sy is nie so vinnig soos haar broer nie. = She is not as fast as her brother.
• Die huis is nie so groot soos ons s'n nie. = The house is not as big as ours.

So so ... soos is the comparison pattern, and the two nie's make it negative.

My means my before a noun:

• my serp = my scarf

But when the noun is left out, Afrikaans often uses the independent possessive pronoun:

• myne = mine

So:

• my serp = my scarf
• die serp is myne = the scarf is mine

In this sentence, myne stands for my scarf:

• Haar serp is nie so lank soos myne nie
• = Her scarf is not as long as mine

This is similar to English my vs mine.

Here, haar means her.

So:

• haar serp = her scarf

Afrikaans haar can be used as a possessive determiner, like English her before a noun.

Examples:

• haar boek = her book
• haar jas = her coat

It is not changing form here; Afrikaans does not do the same kind of adjective agreement that English learners may expect from some other languages.

Afrikaans commonly uses dit to refer back to things, including objects like serp.

So:

• dit = it

In the sentence:

• maar dit is sagter
• = but it is softer

Even though serp is a noun, Afrikaans does not assign grammatical gender in the same way that languages like German do. For ordinary objects, dit is the normal pronoun.

Sagter is the comparative form of sag.

• sag = soft
• sagter = softer

A very common way to form the comparative in Afrikaans is:

adjective + -er

Examples:

• lank → langer = long → longer
• sag → sagter = soft → softer
• oud → ouer = old → older

So dit is sagter simply means it is softer.

Because the comparison is only implied by the context.

The full idea is:

• Her scarf is not as long as mine, but it is softer.

In the second clause, Afrikaans just says:

• maar dit is sagter
• but it is softer

You do not need as or than there, because the listener already understands that the scarf is being compared with mine.

If you wanted to state the comparison more explicitly in another sentence, Afrikaans would use as with a comparative:

• Dit is sagter as myne. = It is softer than mine.

Lank means long in the sense of physical length.

That makes sense for a scarf, because a scarf has measurable length.

Examples:

• 'n lang serp = a long scarf
• 'n lang tou = a long rope

So nie so lank soos myne nie is exactly the kind of phrase you would expect for comparing two scarves.

No, it is just standard Afrikaans main-clause word order.

• maar = but
• dit is sagter = it is softer

Afrikaans main clauses usually keep the verb in the second position:

• Dit is sagter.
• Maar dit is sagter.

So after maar, the clause continues normally.

The standard pattern for equality comparison is so ... soos:

• so lank soos myne

That is the form learners should use confidently.

You may sometimes see or hear variation in informal language, but soos is the normal and safest choice here. For learning purposes, treat:

• so ... soos = as ... as

as the standard rule.

In this sentence, both adjectives are being used predicatively, meaning they come after is:

• is ... lank
• is ... sagter

Predicative adjectives in Afrikaans usually do not take the extra adjective ending that learners may see in other contexts.

Compare:

• Die serp is lank. = The scarf is long.
• Die serp is sagter. = The scarf is softer.

So the forms here are normal because the adjectives come after the verb, not directly before a noun.