Baba atasafisha kutu kwenye mlango wa chuma kesho.

It breaks down like this:

• a- = he/she
• -ta- = future tense
• -safisha = clean / make clean

So atasafisha means he/she will clean.

In this sentence, the subject is Baba, so atasafisha means Father will clean.

Because Swahili usually puts the subject information inside the verb.

So in atasafisha, the a- already tells you he/she.
That means Swahili does not need a separate pronoun like English he.

With the noun present, the pattern is:

• Baba atasafisha = Father will clean

The verb agrees with the subject, so the extra pronoun would normally be unnecessary.

Yes. Kutu is the thing being cleaned, so it functions as the direct object.

That can feel a little different from English, because English often says:

• clean the door
• remove the rust from the door

But Swahili can naturally say something like:

• clean rust on the door

So kutu is the thing being removed/cleaned, while kwenye mlango wa chuma tells you where that rust is.

Kwenye is a very common locative word meaning something like:

• on
• in
• at

The exact English translation depends on context.

Here, with mlango (door), kwenye mlango wa chuma means on the metal door or at the metal door, but in natural English on the metal door is the best fit because rust is on a surface.

So:

• kwenye mlango wa chuma = on the metal door

Because wa must agree with mlango, not with chuma.

Mlango belongs to a noun class that takes wa in this kind of of phrase:

• mlango wa chuma = door of metal / metal door

This agreement is a noun-class feature of Swahili.

A useful comparison:

• mlango wa chuma = metal door
• milango ya chuma = metal doors

Notice how singular mlango takes wa, while plural milango takes ya.

Yes. Very literally, mlango wa chuma means door of metal.

In smoother English, that becomes:

• metal door
• iron door

This is a very common Swahili pattern:

• noun + wa/ya/etc. + noun

It often works like English noun combinations or of phrases.

Chuma can cover iron and more generally metal, depending on context.

So mlango wa chuma could be understood as:

• metal door
• iron door

In many learning contexts, metal door is a safe translation unless the context clearly points to a specific metal.

Yes, kesho can move.

In this sentence, it appears at the end:

• Baba atasafisha kutu kwenye mlango wa chuma kesho.

That is perfectly natural.

But Swahili can also place time expressions earlier for emphasis or style:

• Kesho, Baba atasafisha kutu kwenye mlango wa chuma.

Both mean the same basic thing: Father will clean the rust on the metal door tomorrow.

So kesho is flexible in position, though end position is very normal.

Because Swahili does not have articles like English a/an and the.

So nouns like baba, kutu, and mlango appear without articles.
The listener understands whether something is specific or general from context.

That means mlango wa chuma could mean:

• a metal door
• the metal door

depending on the situation.

Yes. They are closely related.

• safi = clean (adjective)
• safisha = clean / make clean (verb)

So safisha has the sense of make clean.

That is why atasafisha means he will clean.

Yes, sometimes mlango can refer to a door, gate, or entrance, depending on context.

So mlango wa chuma could be understood as:

• metal door
• iron gate

If the wider context is a house, door is likely.
If the context is a compound, fence, or outside entrance, gate may be more natural.