Mwanasayansi alichunguza sampuli.

Alichunguza can be broken down like this:

• a- = he/she
• -li- = past tense marker
• chunguza = examine / investigate / inspect

So alichunguza means he/she examined or he/she investigated.

In this sentence, the subject is mwanasayansi (scientist), so the full idea is the scientist examined the sample.

Swahili usually does not use articles like English a, an, and the.

So:

• mwanasayansi can mean a scientist or the scientist
• sampuli can mean a sample or the sample

The exact meaning depends on context. This is very normal in Swahili.

Mwanasayansi refers to a person, so it behaves like a noun in the m-/wa- class, the common class for human beings.

In the singular:

• mwanasayansi = scientist

In the plural:

• wanasayansi = scientists

The verb agrees with the subject. Since the subject is singular and human, the subject marker is a-:

• mwanasayansi alichunguza = the scientist examined
• wanasayansi walichunguza = the scientists examined

So a- is there because the subject is a singular person.

The plural would be:

Wanasayansi walichunguza sampuli.

Breakdown:

• wanasayansi = scientists
• wa- = they
• -li- = past
• chunguza = examine
• sampuli = sample / samples, depending on context

So this means The scientists examined the sample or The scientists examined the samples, depending on the situation.

Good question. Not all Swahili nouns change form in the same way.

Sampuli is a loanword, and many loanwords do not show obvious singular/plural changes in everyday use. Its number is often understood from context, adjectives, verbs, or surrounding words.

So sampuli may remain the same form whether you mean sample or samples, unless something else in the sentence makes the number clear.

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

• Mwanasayansi = subject
• alichunguza = verb
• sampuli = object

So it matches English structure quite closely:

• The scientist / examined / the sample

That makes sentences like this fairly straightforward for English speakers.

Yes. Swahili verbs usually do not mark gender.

So a- can mean:

• he
• she

That means alichunguza can mean either he examined or she examined. The noun mwanasayansi also does not tell you whether the scientist is male or female.

You only know the gender if the wider context tells you.

You change the tense marker inside the verb.

From chunguza:

• anachunguza = is examining
  • a- = he/she
  • -na- = present/progressive
• atachunguza = will examine
  • a- = he/she
  • -ta- = future

So:

• Mwanasayansi anachunguza sampuli. = The scientist is examining the sample.
• Mwanasayansi atachunguza sampuli. = The scientist will examine the sample.

A helpful rough pronunciation is:

mwa-na-sa-YAN-si

A few tips:

• mw is pronounced together, not as two separate syllables
• stress in Swahili often falls near the second-to-last syllable, so YAN is the strongest part here
• vowels are usually pronounced clearly:
  • a like ah
  • i like ee

So try something like: mwah-nah-sah-YAHN-see

A rough pronunciation guide:

• alichunguza ≈ ah-lee-choon-GOO-zah
• sampuli ≈ sahm-POO-lee

Tips:

• ch sounds like the ch in church
• g in -gu- is a hard g, like in go
• vowels are pure and consistent, unlike English vowels, which often shift

Put together:

ah-lee-choon-GOO-zah sahm-POO-lee

Yes, in some contexts you can add an object marker if the object is already known from context.

For example:

• Mwanasayansi aliichunguza.

Here -i- is an object marker referring to something in the appropriate noun class, such as a previously mentioned sample.

This would mean something like:

• The scientist examined it.

In your original sentence, the full noun sampuli is stated directly, so no object marker is needed.

Chunguza is a useful verb with a range of related meanings, including:

• examine
• inspect
• investigate
• analyze or look into, depending on context

So alichunguza sampuli could be translated in slightly different ways depending on the situation:

• The scientist examined the sample
• The scientist analyzed the sample
• The scientist investigated the sample

The best English choice depends on what kind of scientist and what kind of sample are being discussed.