Malakas ang katawan ko.

Because the most natural basic sentence pattern in Filipino is often predicate first.

So:

• Malakas = the predicate
• ang katawan ko = the topic being described

Literally, the structure is closer to:

• Strong is my body

than to the English order My body is strong.

You can also say:

• Ang katawan ko ay malakas

but that sounds more formal, more written, or more emphatic.

In this sentence, ang marks the topic of the sentence.

So in:

• Malakas ang katawan ko

the phrase ang katawan ko is the thing being talked about.

A very important point: ang is not always the same as English the.
Sometimes learners try to translate it that way, but here its main job is grammatical: it marks the noun phrase as the topic/focus of the sentence.

Because ko is a possessive form meaning my, and in Filipino possessive pronouns like this usually come after the noun.

So:

• katawan ko = my body
• bahay ko = my house
• kaibigan ko = my friend

This is a very common pattern:

• noun + ko/mo/niya/namin/natin/ninyo/nila

Ko is the first-person singular possessive form, meaning my.

In different contexts, ko can also function like I/me in certain grammatical roles, but in katawan ko, it is clearly possessive:

• katawan = body
• katawan ko = my body

So here ko means my, not me.

Not exactly.

• Malakas ako = I am strong
• Malakas ang katawan ko = My body is strong

The first describes you as a whole person.
The second focuses specifically on your body/physical condition.

In many situations, they are similar in meaning, but Malakas ang katawan ko sounds more specifically physical and bodily.

Not always. Malakas has a range of meanings depending on context, such as:

• strong
• powerful
• loud
• intense

Examples:

• Malakas siya. = He/She is strong.
• Malakas ang ulan. = The rain is heavy/strong.
• Malakas ang boses niya. = His/Her voice is loud.

In Malakas ang katawan ko, it usually means physically strong, robust, or sometimes even healthy/with a strong constitution, depending on context.

Yes. In Filipino, talking about the body being malakas can suggest more than just muscle strength.

It can imply:

• physically strong
• hardy
• not sickly
• having a strong constitution

So depending on context, it may mean something like:

• My body is strong
• I have a strong body
• I’m physically robust

It does not automatically mean bodybuilder-style muscular strength.

Because Filipino often does not need a verb equivalent to English is/am/are in simple descriptive sentences.

English:

• My body is strong

Filipino:

• Malakas ang katawan ko

There is no separate word for is here. This is normal and very common in Filipino.

Yes, that is grammatical.

Compare:

• Malakas ang katawan ko = natural, common, conversational
• Ang katawan ko ay malakas = more formal, more literary, or more contrastive/emphatic

Both mean the same basic thing.
In everyday speech, the first version is usually more natural.

You usually use hindi:

• Hindi malakas ang katawan ko.

This means:

• My body is not strong.

The pattern is:

• Hindi + predicate + ang-phrase

So:

• Malakas ang katawan ko.
• Hindi malakas ang katawan ko.

A common way is to add ba:

• Malakas ba ang katawan ko?

This means:

• Is my body strong?

The particle ba marks a yes/no question.
It usually comes after the first element of the sentence, which here is malakas.

The base is katawan, which means body. For most learners, it is best to memorize it as a whole vocabulary word.

If you study morphology later, you may notice that many Filipino words are built with affixes, but for practical beginner use, just learn:

• katawan = body

Then combine it with possessives:

• katawan ko = my body
• katawan mo = your body
• katawan niya = his/her body

Yes, it is grammatical and natural, especially if you want to emphasize the body or physical condition.

That said, depending on context, native speakers might also say things like:

• Malakas ako. = I’m strong.
• Malusog ako. = I’m healthy.
• Matibay ang katawan ko. = I have a sturdy/robust body.
• Malakas ang pangangatawan ko. = I have a strong physique/constitution.

So Malakas ang katawan ko is fine, but there are other natural ways to express related ideas depending on the exact meaning you want.