Dadah menjejaskan kesihatan.

In this sentence, dadah means drugs, usually in the sense of narcotics or illegal/harmful drugs.

It normally does not mean medicine in everyday Malay. For medicine, Malay usually uses ubat.

So:

• dadah = drugs, especially harmful/illegal drugs
• ubat = medicine

Menjejaskan means to negatively affect, to harm, or to impair.

In Dadah menjejaskan kesihatan, it means that drugs have a bad effect on health.

It is a little broader than just destroy. It can mean:

• harm
• damage
• adversely affect
• impair

So the sentence is not saying health is completely ruined, only that it is harmed or affected badly.

This is the normal Malay word order: Subject + Verb + Object, just like basic English.

• Dadah = subject
• menjejaskan = verb
• kesihatan = object

So it literally follows:

• Drugs
  • harm/affect
    • health

That makes this sentence very straightforward grammatically.

Malay often builds verbs by adding prefixes and suffixes to a root word.

Menjejaskan can be understood as:

• root: jejas
• prefix: men-
• suffix: -kan

Together, they form an active transitive verb meaning to adversely affect something.

You do not always need to break every verb apart when learning, but it helps to know that Malay commonly does this. The important thing here is:

• menjejaskan is an active verb
• it usually takes an object
• the object here is kesihatan

Kesihatan means health.

It comes from the adjective sihat, which means healthy.

Malay often uses ke-...-an to turn a word into an abstract noun. So:

• sihat = healthy
• kesihatan = health

This is a very useful pattern to recognize.

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

So kesihatan can mean:

• health
• the health
• your health
• public health

The exact meaning depends on context.

In this sentence, it is a general statement, so kesihatan is best understood as health in a broad sense.

If you want to be more specific, you can add a pronoun, for example:

• kesihatan anda = your health
• kesihatan kita = our health

Malay nouns often do not change form for singular and plural.

So dadah can mean:

• drug
• drugs

The context tells you which meaning is intended.

In this sentence, the meaning is drugs in general, or even drug use as a general idea.

Malay can show plural by repeating a noun, but that would sound unnatural here. A sentence like this is normally kept simple and generic.

In normal usage, this sentence is a general warning. It usually means something like:

• drugs are harmful to health
• drug use harms health
• drug abuse harms health

Because dadah often refers to harmful or illegal drugs, the sentence naturally has a negative meaning.

If you want to be more precise, you could say:

• Penyalahgunaan dadah menjejaskan kesihatan = Drug abuse harms health

But Dadah menjejaskan kesihatan is very natural as a general statement.

Yes, absolutely.

• Dadah menjejaskan kesihatan = Drugs harm health
• Dadah menjejaskan kesihatan kita = Drugs harm our health

Adding kita makes it more personal or explicit.

Without kita, the sentence is more general and slogan-like. That is why the shorter version is common.

A simple rough guide is:

• Dadah = DAH-dah
• menjejaskan = mən-jə-JAS-kan
• kesihatan = kə-si-HA-tan

A few helpful notes:

• j in Malay sounds like the j in jam
• e in many unstressed syllables often sounds like a soft uh
• stress in Malay is usually not as strong as in English, but a rough English-friendly pronunciation is still useful

So the whole sentence sounds roughly like:

DAH-dah mən-jə-JAS-kan kə-si-HA-tan

Yes, but the active version is simpler and more natural for learners.

Active:

• Dadah menjejaskan kesihatan = Drugs harm health

Possible passive:

• Kesihatan dijejaskan oleh dadah = Health is harmed by drugs

Another very natural alternative is:

• Kesihatan terjejas akibat dadah = Health is affected because of drugs

For everyday learning, the active sentence is the best one to start with.