Perosak merosakkan tumbuhan ini.

Yes, they are related. Both come from the root rosak, which has the basic idea of being damaged, spoiled, broken, or ruined.

• perosak = a pest / a destroyer / something that causes damage
• merosakkan = to damage / to ruin something

So the sentence uses:

• perosak as the subject noun
• merosakkan as the verb

This kind of word-building is very common in Malay.

Rosak usually describes a state: something is damaged or broken.

• Tumbuhan ini rosak = This plant is damaged.

But merosakkan is a transitive verb, meaning it takes an object and means to damage something.

• Perosak merosakkan tumbuhan ini = The pest damages this plant.

So:

• rosak = be damaged / broken
• merosakkan = damage something

That -kan helps make it an action done to an object.

Perosak literally means something like damager or destroyer, but in everyday use it often means pest, especially in farming or gardening contexts.

Depending on context, it could refer to:

• insects
• plant pests
• harmful organisms
• things that damage crops or plants

So in this sentence, perosak is most naturally understood as a pest or pests.

That is normal Malay word order.

In Malay, demonstratives like:

• ini = this / these
• itu = that / those

usually come after the noun.

So:

• tumbuhan ini = this plant / these plants
• rumah itu = that house

This is one of the most common differences from English.

It can depend on context, because Malay often does not mark singular and plural explicitly.

• tumbuhan can mean plant or plants, depending on the situation.
• ini can mean this or these, again depending on context.

So tumbuhan ini could mean:

• this plant
• these plants

If the intended meaning shown to the learner is singular, then translate it as this plant. If the context is plural, it could be these plants.

Malay often leaves number to context unless it needs to be made very clear.

Malay normally does not use articles like English a, an, or the.

So a sentence like:

• Perosak merosakkan tumbuhan ini

does not need extra words for the pest or a pest.

The exact English choice depends on context:

• A pest damages this plant
• The pest damages this plant
• Pests damage this plant

Malay often leaves definiteness unstated unless context makes it clear.

It can be either singular or plural, depending on context.

Malay nouns are often number-neutral unless something in the sentence shows otherwise.

So perosak could mean:

• a pest
• the pest
• pests

If you want to show plural clearly, Malay can use reduplication:

• perosak-perosak = pests

But in many real sentences, Malay does not bother marking plural if the meaning is already obvious.

Yes. This sentence follows the common Subject–Verb–Object order:

• Perosak = subject
• merosakkan = verb
• tumbuhan ini = object

So the structure is:

Perosak | merosakkan | tumbuhan ini
Pest(s) | damage | this plant

That makes this sentence fairly straightforward for English speakers.

Not exactly.

• tumbuhan = plant / vegetation / flora
• pokok often means tree, but in everyday Malay it can also mean plant, depending on context

So tumbuhan sounds a bit more general or formal than pokok. In a sentence about pests, tumbuhan is very natural if you are talking about plants in a general or scientific sense.

A simple way to see it is:

Root:

• rosak = damaged / broken / spoiled

Derived forms:

• peN- + rosak → perosak = one that damages, so pest / destroyer
• meN- + rosak + -kan → merosakkan = to damage something

You do not need to master all the morphology at once, but it helps to notice:

• meN- often forms active verbs
• peN- often forms nouns for the doer or agent
• -kan often helps make a verb act on an object

So the sentence is built very systematically from one root.

Yes. A common passive version would be:

Tumbuhan ini dirosakkan oleh perosak.

That means: This plant is damaged by pests or This plant is being damaged by the pest.

Breakdown:

• Tumbuhan ini = this plant
• dirosakkan = is damaged
• oleh perosak = by the pest / by pests

Malay uses di- for many passive verbs.

A simple learner-friendly pronunciation is:

meh-roh-sak-kan

A few tips:

• e in me- is often like a soft uh sound
• r is usually tapped or lightly rolled
• every written vowel is pronounced clearly
• kk in spelling does not mean a long consonant in the English sense; just pronounce both syllables clearly: sa-kan

So the whole sentence would sound roughly like:

pe-roh-sak meh-roh-sak-kan tum-boo-han ee-nee

That is only an approximation, but it is a useful start.

Standard Malay uses merosakkan here, not merosak.

That is because merosakkan is the normal transitive form meaning to damage something.

So:

• merosakkan tumbuhan ini = damage this plant

Using merosak would sound nonstandard in formal Malay. For learners, it is best to remember merosakkan as the correct form in this pattern.