Die brilvoorskrif bepaal die lenssterkte.

Die is the definite article in Afrikaans, so it usually means the.

It appears twice because there are two definite nouns in the sentence:

• die brilvoorskrif = the glasses prescription / the eyeglass prescription
• die lenssterkte = the lens strength / the lens power

Unlike in English, Afrikaans uses die for all nouns in the definite form, regardless of gender.

Yes. Afrikaans very often forms compound nouns by writing them as a single word.

So:

• bril = glasses
• voorskrif = prescription

Together:

• brilvoorskrif = glasses prescription / eyeglass prescription

This is very normal in Afrikaans, and English learners often need to get used to the fact that words that may be separate in English are often written together in Afrikaans.

Voorskrif usually means prescription.

It can be used in medical contexts, including:

• a doctor's prescription
• an eyeglass prescription

In this sentence, because of bril-, it specifically refers to an optical prescription, not a medicine prescription.

Yes.

It is made up of:

• lens = lens
• sterkte = strength

So lenssterkte literally means lens strength, and in context it can also be understood as lens power.

Again, Afrikaans commonly joins these parts into one compound noun.

Bepaal means determine, decide, or set, depending on context.

In this sentence, bepaal means something like:

• determines
• decides
• sets

So the idea is that the eyeglass prescription determines what lens strength is needed.

Because Afrikaans verbs usually do not change form the way English verbs do in the present tense.

In English:

• I determine
• he determines

In Afrikaans, the verb usually stays the same:

• ek bepaal
• hy bepaal
• die brilvoorskrif bepaal

That is one of the simpler features of Afrikaans grammar.

The sentence follows the normal main-clause Afrikaans pattern:

Subject + Verb + Object

• Die brilvoorskrif = subject
• bepaal = verb
• die lenssterkte = object

So it works very much like standard English word order here.

Afrikaans does not use grammatical gender the way languages like German do.

That is why die is used as the for nouns in general, instead of having different forms for masculine, feminine, and neuter nouns.

So learners do not need to memorize noun gender for sentences like this.

A rough English-friendly guide would be:

• brilvoorskrif ≈ bril-FOHR-skrift
• lenssterkte ≈ LENS-sterk-tuh

A few helpful notes:

• bril sounds a bit like English brill
• voor has a long vowel, somewhat like for, but not exactly English
• skrif sounds close to skrift
• sterk sounds like sterk with a rolled or tapped r in many accents
• the final -te in sterkte is a light unstressed ending

Pronunciation varies somewhat by accent, but those approximations are enough to get started.

Yes. Depending on context, natural translations could include:

• The eyeglass prescription determines the lens strength.
• The glasses prescription determines the lens power.
• The prescription determines the strength of the lenses.

The Afrikaans sentence is compact, and English may choose slightly different wording depending on whether the context is optometry, retail, or everyday speech.

Because Afrikaans often prefers compounds where English might use an of phrase.

So instead of something like:

• die sterkte van die lens

it uses the compound:

• die lenssterkte

Both patterns can exist in Afrikaans, but compounds are extremely common and often sound more natural and efficient.

Yes. Bril is the normal Afrikaans word for glasses or spectacles.

So brilvoorskrif is the prescription for glasses, not for contact lenses in general. If the context were specifically contact lenses, Afrikaans might use different wording.

Grammatically, the main subject is singular:

• Die brilvoorskrif = The prescription

And the object is also singular in form:

• die lenssterkte = the lens strength

Even though bril refers to something that is plural in English sense (glasses), the compound noun brilvoorskrif is treated as a single singular noun in Afrikaans.