As 'n vrieskas ooit ontdooi, sal die kos bederf.

No. In this sentence, As means if.

So:

• As 'n vrieskas ooit ontdooi ... = If a freezer ever defrosts / thaws ...

This is a very common point for English speakers, because Afrikaans as often corresponds to English if, not English as.

'n is the Afrikaans indefinite article, equivalent to English a / an.

So:

• 'n vrieskas = a freezer

A few useful notes:

• It is written as 'n, with an apostrophe.
• It is usually not stressed in speech.
• At the beginning of a sentence, you usually capitalize the following word, not the article itself. So you may see:
  • 'n Vrieskas ...

Vrieskas means freezer.

It is made up of:

• vries = freeze
• kas = cupboard / cabinet / box

So literally it is something like a freezing cabinet, but the normal English translation is simply freezer.

Ooit means ever here.

So:

• As 'n vrieskas ooit ontdooi ...
• If a freezer ever defrosts ...

It adds a sense of at any time or if this ever happens.

Without ooit, the sentence would still make sense:

• As 'n vrieskas ontdooi, sal die kos bederf.

But ooit makes it sound more general or more hypothetical.

Because As introduces a subordinate clause, and in Afrikaans, the verb in a subordinate clause typically goes to the end.

So:

• As 'n vrieskas ooit ontdooi
  • literally: If a freezer ever defrosts

This word order is very normal in Afrikaans after words like:

• as = if
• dat = that
• omdat = because
• wanneer = when

For an English speaker, this is one of the most important grammar patterns to get used to.

Because the sentence begins with the if-clause, and that affects the word order in the main clause.

Afrikaans main clauses normally follow a verb-second pattern. When the sentence starts with something other than the subject—here, the whole clause As 'n vrieskas ooit ontdooi—the finite verb comes before the subject in the next clause.

So you get:

• As 'n vrieskas ooit ontdooi, sal die kos bederf.

Not:

• As 'n vrieskas ooit ontdooi, die kos sal bederf.

This is similar to inversion in some formal English structures, but it is much more regular in Afrikaans.

Sal means will.

So:

• sal die kos bederf = the food will spoil

It marks the future or a predicted result.

This gives the sentence the structure:

• If X happens, Y will happen.

Here, bederf means spoil, go bad, or become rotten.

So:

• die kos bederf = the food spoils / the food will spoil

Be careful, because depending on context, bederf can also have other related meanings, such as ruin or spoil in the sense of overindulging someone. But in this sentence, with food, it clearly means go bad.

Yes. In this context, ontdooi can be translated as defrost or thaw.

So:

• 'n vrieskas ontdooi = a freezer defrosts / thaws out

Depending on the exact context, English might choose one or the other:

• defrost if you are thinking of a freezer losing its frost or thawing out
• thaw if you are thinking more generally of something no longer being frozen

The comma separates the subordinate clause from the main clause:

• As 'n vrieskas ooit ontdooi, = if-clause
• sal die kos bederf. = main clause

This is standard punctuation in Afrikaans, just as in English you would normally write:

• If a freezer ever defrosts, the food will spoil.

Not without changing the meaning.

• As = if
• wanneer = when

So:

• As 'n vrieskas ooit ontdooi ... = If a freezer ever defrosts ...
• Wanneer 'n vrieskas ontdooi ... = When a freezer defrosts ...

English sometimes uses when and if quite loosely, but Afrikaans keeps this distinction clear. In your sentence, As is the right choice because it expresses a condition, not a certain event.

It is phrased in a general way.

• 'n vrieskas = a freezer
• die kos = the food

This is like a general rule:

• If a freezer ever defrosts, the food will spoil.

So it does not necessarily mean one particular freezer in a specific situation. It sounds more like a general warning or statement of fact.