Ons bemes die basiliekruid met kunsmis.

Yes. In this sentence, ons means we.

Afrikaans ons can also mean us, depending on the sentence:

• Ons bemes die basiliekruid. = We fertilize the basil.
• Hulle help ons. = They help us.

So ons covers both subject we and object us.

Bemes means to fertilize or to manure.

It comes from the noun mis, which can mean manure. In modern everyday use, bemes is the normal verb for fertilizing plants or soil.

So:

• Ons bemes die basiliekruid = We fertilize the basil

No. In Afrikaans, verbs usually do not change form depending on the subject.

So you get:

• Ek bemes = I fertilize
• Jy bemes = you fertilize
• Ons bemes = we fertilize
• Hulle bemes = they fertilize

This is much simpler than English, where you have forms like I am / he is or I have / she has.

Yes. Die here means the.

Afrikaans uses die as the definite article for all nouns, whether singular or plural:

• die plant = the plant
• die plante = the plants
• die basiliekruid = the basil

Unlike languages such as German or Dutch, Afrikaans does not have different forms of the for different genders or cases. It is simply die.

Met kunsmis means with fertilizer.

So the sentence structure is:

• Ons = we
• bemes = fertilize
• die basiliekruid = the basil
• met kunsmis = with fertilizer

English also allows this structure:

• We fertilize the basil with fertilizer.

The phrase met kunsmis tells you what is being used to do the fertilizing.

Kunsmis means fertilizer.

Literally, it is made up of:

• kuns = artificial / art / synthetic
• mis = manure

So kunsmis is basically artificial manure, which is why it means fertilizer.

This is a very common Afrikaans word.

Yes, basiliekruid is normally written as one word in Afrikaans.

Afrikaans often forms compound nouns as single words. That is very common:

• sonlig = sunlight
• huiswerk = homework
• tuinmaak = gardening
• basiliekruid = basil herb / basil

So if you are used to English spelling compounds separately, Afrikaans may look more compact.

This sentence uses the standard Afrikaans main-clause order:

Subject + Verb + Object + Other information

So:

• Ons = subject
• bemes = verb
• die basiliekruid = object
• met kunsmis = prepositional phrase

That makes it a very straightforward sentence.

Afrikaans main clauses usually place the finite verb in the second position, and here that gives:

• Ons bemes ...

Yes, you could, but it is slightly different in emphasis.

• Ons bemes die basiliekruid met kunsmis. = We fertilize the basil with fertilizer.
• Ons gee die basiliekruid kunsmis. = We give the basil fertilizer.

Both are natural, but:

• bemes focuses on the action of fertilizing
• gee ... kunsmis focuses more on giving fertilizer

So the original sentence is a bit more specific and agricultural/gardening-oriented.

A rough English-friendly guide is:

ba-SI-li-krœyt
or more loosely
bah-SEE-lee-kroyd

A few notes:

• ie in Afrikaans is usually like ee in see
• ui is a typical Dutch/Afrikaans vowel sound that does not match English exactly; an approximation like oy or ay-uh is often given for beginners
• kruid sounds somewhat like kroyd to English ears

You do not need perfect pronunciation immediately; being understood is more important.

In theory, die can be both singular and plural, but basiliekruid itself is usually understood here as a singular mass-like noun: the basil.

So:

• die basiliekruid = the basil

If you were talking about multiple basil plants, context would usually make that clear, or you might use a different phrasing such as:

• die basilieplante = the basil plants

So in this sentence, most learners should understand die basiliekruid as the basil (plant/herb).