Learn Hardcore Indonesian: Dia mengikuti kelas senam untuk dewasa supaya tubuhnya tetap kuat dan lentur. - She attends a gymnastics class for adults so that her body stays strong and flexible.

Indonesian third‑person pronouns don’t mark gender.
To know whether Dia is he or she, you rely on:
- context from the conversation, or
- extra words like pria (man), wanita (woman), laki-laki, perempuan, suami (husband), istri (wife), etc.

So Dia mengikuti kelas senam… can be He attends an aerobics class… or She attends an aerobics class…, depending on context.

What exactly does mengikuti mean here? Why not just ikut?

The base verb is ikut, which means to join / to go along / to take part.

Mengikuti is the meN‑ form of ikut and often has a slightly more formal or more specific sense, like:

to follow (a course, event)
to attend
to take part in (systematically, as a participant)

In this sentence:

Dia mengikuti kelas senam… ≈ He/She attends an aerobics class…

You could say:

Dia ikut kelas senam…

This is more casual and can sound a bit less formal or less “program-like,” but it’s still correct and understandable. Mengikuti sounds more like officially taking / attending a course.

What does kelas senam mean literally? Is senam the same as “exercise” or “gym”?

Literally:

kelas = class
senam = gymnastics / aerobics / workout-type exercise

Senam often refers to:

organized, usually rhythmic exercise (like aerobics, group fitness, morning calisthenics),
not weightlifting in a gym, and not sports games like football.

So kelas senam is best translated as something like:

aerobics class
exercise class
fitness / workout class (especially in a group, with an instructor)

For generic “exercise” or “sports,” Indonesians often say olahraga.
Kelas olahraga would sound more like sports class (e.g. school P.E. class), not specifically an aerobics session.

What does untuk dewasa do in this sentence? Is it the same as saying “adult class”?

Untuk dewasa literally means for adults.

untuk = for
dewasa = adult / mature

So kelas senam untuk dewasa = an exercise class for adults or an adult aerobics class.

Grammatically:

kelas (noun)
senam (noun describing the class type)
untuk dewasa (prepositional phrase specifying who it is for)

This is a common pattern:

buku untuk anak-anak = a book for children
film untuk keluarga = a movie for families

So untuk dewasa is not saying the class itself is adult (in age) but that the target participants are adults.

What’s the function of supaya? How is it different from untuk or agar?

Supaya introduces a purpose or desired result: so that / in order that.

In the sentence:

…supaya tubuhnya tetap kuat dan lentur.
= …so that his/her body stays strong and flexible.

Common comparisons:

supaya and agar:
- Very similar in meaning (so that / in order that).
- Agar is often a bit more formal or written; supaya is very common in speech.
- You can usually swap them:
  - supaya tubuhnya tetap kuat…
  - agar tubuhnya tetap kuat…
untuk:
- untuk
  - verb usually means in order to / to (do something), often with the subject implied.
- Example: Dia mengikuti kelas senam untuk menjaga tubuhnya tetap kuat.
  = He/She attends the class to keep his/her body strong.
- With supaya/agar, you usually have a full clause after it.

So:

Dia mengikuti kelas senam supaya tubuhnya tetap kuat…
= He/She takes the class so that the body stays strong…

Both supaya and agar are fine here; supaya feels very natural in speech.

What does tubuhnya mean exactly? How does the suffix -nya work here?

Breakdown:

tubuh = body
-nya = a third-person marker that often means his / her / its / their (singular)

So tubuhnya = his/her body.

About -nya:

Possessive pronoun:
- rumahnya = his/her house
- bukunya = his/her book
- tubuhnya = his/her body
It can also mean the (definite marker) in some contexts, but here the possessive reading is natural.

Since Dia is the subject, tubuhnya refers back to that same person:
Dia… supaya tubuhnya tetap kuat… = He/She… so that his/her body stays strong…

Could we say supaya dia tetap kuat dan lentur instead of supaya tubuhnya tetap kuat dan lentur?

Yes, you can say:

Dia mengikuti kelas senam untuk dewasa supaya dia tetap kuat dan lentur.
= He/She attends an adult aerobics class so that he/she stays strong and flexible.

Differences:

supaya tubuhnya tetap kuat dan lentur
- Focuses specifically on the body staying strong and flexible.
supaya dia tetap kuat dan lentur
- Focuses on the person as a whole being strong and flexible.

Both are grammatically correct. The original sentence just highlights the physical body explicitly.

What does tetap add here? How is it different from masih or selalu?

Tetap means to remain / to stay (in the same state).

In this sentence:

tetap kuat dan lentur = stay strong and flexible (not become weak or stiff)

Compare:

masih = still (not yet changed or finished)
- Dia masih kuat. = He/She is still strong (hasn’t stopped being strong yet).
selalu = always (habitually, repeatedly)
- Dia selalu kuat. = He/She is always strong (a consistent trait).

Tetap emphasizes maintaining a condition over time:

Saya ingin tetap sehat. = I want to stay healthy.
Supaya tubuhnya tetap kuat dan lentur. = So that the body remains strong and flexible.

Using masih or selalu here would change the meaning and be less natural in this context.

Why are the adjectives after the noun in tubuhnya tetap kuat dan lentur? Can we move them before?

In Indonesian, adjectives normally come after the noun:

tubuh kuat = strong body
orang dewasa = adult person
rumah besar = big house

In the sentence:

tubuhnya tetap kuat dan lentur
literally: her/his body stays strong and flexible

You generally do not put adjectives before the noun the way English does. Saying something like kuat tubuhnya is possible, but:

It sounds more like a comment or emphasis: Kuat tubuhnya! = “How strong his/her body is!”
It’s not the neutral noun phrase order like in English.

So you should keep kuat and lentur after tubuhnya in this kind of descriptive clause.

What does lentur mean? Is it the same as “flexible,” “elastic,” or “stretchy”?

Lentur generally means:

flexible / supple, especially physically:
- a flexible body
- a supple back
- something that can bend without breaking

Example:

Tubuh penari itu sangat lentur. = That dancer’s body is very flexible.

Nuances:

For stretchy / elastic materials (like rubber bands, fabric), Indonesians often use elastis or context-specific words.
Lentur is usually used for:
- bodies, joints, spines
- sometimes rods, branches, or objects that bend easily

So kuat dan lentur together is a natural collocation for describing a body that is both strong and flexible.

Is this sentence formal or informal? Would it sound natural in everyday conversation?

The sentence:

Dia mengikuti kelas senam untuk dewasa supaya tubuhnya tetap kuat dan lentur.

is in neutral–slightly formal Indonesian:

mengikuti and tubuh are a bit more formal than some everyday alternatives.
It would sound fine in:
- written explanations,
- a health article,
- polite conversation.

More casual versions could be:

Dia ikut kelas senam buat orang dewasa biar badannya tetap kuat dan lentur.
- buat instead of untuk
- biar instead of supaya
- badan instead of tubuh

So yes, the original is natural, just slightly more on the standard/formal side.

Can any parts of this sentence be dropped in casual speech and still be understood?

Yes, Indonesian often drops elements when they’re clear from context.

Possible omissions:

Dropping Dia (if the subject is already known):
- Mengikuti kelas senam untuk dewasa supaya tubuhnya tetap kuat dan lentur.
  In a conversation where the person is already obvious, this is fine.
Shortening the purpose clause:
- …supaya tetap kuat dan lentur.
  (dropping tubuhnya)
- Context would make it clear that we’re talking about the body.
Making it more colloquial overall:
- Dia ikut kelas senam dewasa supaya tetap kuat dan lentur.

However, the original full sentence is very clear and correct, especially for learners.