Gebruik die waterpas in plaas daarvan om te raai.

Yes. Gebruik is an imperative here, so the sentence is giving an instruction:

Gebruik die waterpas ... = Use the spirit level ...

In Afrikaans, commands often use the plain verb form without an explicit subject.

• Jy gebruik die waterpas. = You use the spirit level.
• Gebruik die waterpas! = Use the spirit level!

So there is an understood you, but it is not said.

Waterpas means spirit level or bubble level.

It is a normal Afrikaans noun, and in this sentence it refers to the tool you use to check whether something is level.

So:

• die waterpas = the spirit level

Do not read it as something like water pass in English; it is a single noun with its own meaning.

Yes. Die is the Afrikaans definite article, so here it means the.

A useful thing for English speakers: Afrikaans does not have separate words like the for different genders or cases. Die is used very widely for the, including with both singular and plural nouns.

So:

• die waterpas = the spirit level
• die huise = the houses

This whole expression means instead of when it is followed by an action.

So in this sentence:

• in plaas daarvan om te raai = instead of guessing

Literally, the pieces are something like:

• in plaas = in place
• daarvan = of that / thereof
• om te raai = to guess

But you should learn in plaas daarvan om as a set phrase meaning instead of before a verb phrase.

Because Afrikaans usually uses om te + infinitive in this kind of structure.

Here, raai is the verb to guess, and after in plaas daarvan you normally get:

• om te + verb

So:

• om te raai = to guess

This is similar to how English often uses to before a verb, but Afrikaans commonly has both om and te in these infinitive constructions.

Raai means guess.

It is a very common everyday verb. For example:

• Ek raai. = I guess.
• Moenie raai nie. = Don't guess.

In your sentence, te raai means to guess or guessing, depending on how naturally you translate it into English.

Usually, in plaas van is used before a noun, while in plaas daarvan om is used before a verb/action.

Compare:

• in plaas van die waterpas = instead of the spirit level
• in plaas daarvan om te raai = instead of guessing

So in your sentence, because guessing is an action, in plaas daarvan om te raai is the standard choice.

The sentence is built very straightforwardly:

• Gebruik — verb in command form
• die waterpas — the object
• in plaas daarvan om te raai — a phrase explaining instead of guessing

So the structure is basically:

Verb + object + instead-of phrase

If you turned it into a normal statement with a subject, it would look like this:

• Jy gebruik die waterpas in plaas daarvan om te raai.

That means You use the spirit level instead of guessing.

Yes. A fairly literal breakdown would be:

• Gebruik = Use
• die waterpas = the spirit level
• in plaas daarvan om te raai = in place of that, to guess / more naturally instead of guessing

Natural English:

• Use the spirit level instead of guessing.

So the overall meaning is simple, even though the Afrikaans phrase in plaas daarvan om is more idiomatic than the English instead of.