Sy snoei die basiliekruid sonder dat sy te veel sny.

They are related, but not exactly the same.

• snoei means to prune, to trim, or to cut back, especially with plants.
• sny is the more general verb to cut.

So Sy snoei die basiliekruid ... tells you she is doing the specific gardening action of pruning the basil plant.
Then ... sonder dat sy te veel sny adds that she is not cutting too much while doing it.

In natural English, this is like saying:

She is pruning the basil without cutting off too much.

Sonder dat means without followed by a full clause.

A useful way to think of it is:

• sonder = without
• dat introduces a subordinate clause

So sonder dat sy te veel sny literally looks something like:

without that she cuts too much

But in natural English, you would usually say:

without cutting too much
or
without her cutting too much

Afrikaans often uses sonder dat when it wants a full clause with its own subject and verb.

Because sonder dat is followed by a full clause, and a full clause normally needs its own subject.

So in:

sonder dat sy te veel sny

the second sy is the subject of sny.

Afrikaans does not leave that subject out here. Even though it is the same person as in the main clause, the subordinate clause still says sy.

Because dat introduces a subordinate clause, and in Afrikaans subordinate clauses usually send the finite verb to the end.

So:

• Main clause: Sy snoei die basiliekruid
• Subordinate clause: dat sy te veel sny

That final word order is very common in Afrikaans after words like dat, omdat, terwyl, as, and similar clause-introducing words.

This is one of the most important word-order patterns for English speakers to learn, because English usually does not move the verb to the end in the same way.

Te veel means too much or too many.

Here it means:

to cut too much

So:

• sy sny te veel = she cuts too much
• sy sny baie = she cuts a lot

That is an important difference:

• baie = a lot / very
• te veel = too much

So if you say te veel, you are saying the amount is excessive.

Yes. A very natural alternative is:

Sy snoei die basiliekruid sonder om te veel te sny.

This is often a structure learners see early on:

• sonder om ... te
  • infinitive

Both versions are possible, but they work a little differently:

• sonder dat sy te veel sny = uses a full subordinate clause
• sonder om te veel te sny = uses an infinitive construction

Since the subject is the same in both parts of the sentence, many speakers would find the sonder om ... te version especially natural.

Basiliekruid means basil.

It is a compound noun:

• basilie = basil
• kruid = herb

Afrikaans, like Dutch and German, very often writes compound nouns as one word. So instead of writing basil herb as two words, Afrikaans joins the parts together:

basiliekruid

This is a very common pattern in the language.

Die is the definite article, meaning the.

So:

• die basiliekruid = the basil

It shows that we are talking about a specific basil plant or a specific amount of basil already understood from the context.

Also, Afrikaans uses die for both singular and plural nouns, so you do not have to learn different forms like English the versus something else. It is simply die.

Not always. Sy can be confusing because it can have more than one function in Afrikaans.

In this sentence, both instances of sy mean she, because they are subjects:

• Sy snoei ... = She prunes ...
• ... dat sy te veel sny = ... that she cuts too much

But elsewhere, sy can also mean his as a possessive, depending on the sentence.

So the meaning of sy depends on its grammar role in the sentence. Here, it is clearly the subject pronoun she both times.