Watoto wana njaa baada ya kucheza mpira uwanjani.

Watoto means children.

Swahili usually does not use articles like the or a/an. So watoto can mean:

• children
• the children

The exact meaning depends on context.

In Swahili, wana njaa literally breaks down as:

• wa- = subject marker for they (for people in the wa- noun class)
• -na = have
• njaa = hunger

So wana njaa literally means they have hunger, but in natural English that is they are hungry.

This is a very common Swahili pattern:

• ana kiu = he/she is thirsty (literally has thirst)
• nina njaa = I am hungry (literally I have hunger)

The wa- part agrees with watoto.

Swahili nouns belong to noun classes, and mtoto / watoto (child / children) belongs to the m-/wa- class for people:

• singular: mtoto
• plural: watoto

Because watoto is plural and refers to people, the verb uses the plural subject marker wa-:

• watoto wana... = the children they-have...

This agreement is a major feature of Swahili grammar.

The singular would be:

Mtoto ana njaa.
= The child is hungry.

Breakdown:

• mtoto = child
• a- = he/she
• -na = have
• njaa = hunger

So:

• watoto wana njaa = children are hungry
• mtoto ana njaa = a/the child is hungry

Baada ya means after.

In this sentence:

• baada ya kucheza mpira = after playing football

This is a fixed and very common expression in Swahili.

Examples:

• baada ya kula = after eating
• baada ya kazi = after work
• baada ya shule = after school

Kucheza is the infinitive form of the verb to play.

In Swahili, the infinitive usually begins with ku-:

• kula = to eat
• kunywa = to drink
• kucheza = to play

After baada ya, Swahili commonly uses this infinitive form:

• baada ya kucheza = after playing
• baada ya kusoma = after studying

So kucheza works a bit like playing in English here.

It can mean both to play and to dance, depending on context.

Examples:

• kucheza mpira = to play football/soccer
• kucheza muziki or kucheza dansi = to dance

In your sentence, because it says mpira, the meaning is clearly to play football.

Here mpira means football or soccer.

Literally, mpira can also mean ball, and in some contexts it can even refer to things made of rubber. But in the phrase kucheza mpira, it usually means to play football/soccer.

So:

• mpira = ball / football, depending on context
• kucheza mpira = to play football

Uwanjani means at the field, on the मैदान/playground, or in the field area, depending on context.

It comes from:

• uwanja = field, ground, playground, court
• -ni = a locative ending, often meaning in, at, on, to

So:

• uwanja = field/ground
• uwanjani = at/on the field

This -ni ending is very common in Swahili:

• shule = school → shuleni = at school
• nyumba = house → nyumbani = at home
• soko = market → sokoni = at the market

The sentence follows a very common Swahili order:

Watoto | wana njaa | baada ya kucheza mpira | uwanjani
Children | are hungry | after playing football | on the field

So the structure is roughly:

subject + verb phrase + time phrase + place phrase

Swahili word order is often similar to English, which makes many sentences easier for English speakers to follow.

Yes, it could, depending on what you want to emphasize.

For example:

• Watoto wana njaa baada ya kucheza mpira uwanjani.
• Watoto wana njaa baada ya kucheza uwanjani.
• Uwanjani, watoto wana njaa baada ya kucheza mpira.

All of these are understandable, though the original sentence sounds very natural.

The exact placement of time and place expressions in Swahili can be somewhat flexible.

Because in Swahili, the subject and part of the verb are often built into one word.

In wana:

• wa- = they
• -na = have

So instead of separate words like English they are or they have, Swahili often combines the subject marker with the verb stem.

That is why wana njaa is enough to mean they are hungry.

Not perfectly. A very literal translation would be something like:

Children have hunger after playing ball at the field.

That helps show the structure, but natural English is:

The children are hungry after playing football on the field.

This is a good example of why it helps to understand both:

• the literal structure
• the natural meaning

A natural negative version is:

Watoto hawana njaa baada ya kucheza mpira uwanjani.
= The children are not hungry after playing football on the field.

Breakdown:

• ha- = negative marker
• wa- = they
• -na = have

So:

• wana njaa = they are hungry
• hawana njaa = they are not hungry

You could ask:

Je, watoto wana njaa baada ya kucheza mpira uwanjani?
= Are the children hungry after playing football on the field?

Or in everyday speech, just say it with question intonation:

Watoto wana njaa baada ya kucheza mpira uwanjani?

The word je is optional and is often used to make a yes/no question clearer.

A useful vocabulary list is:

• mtoto = child
• watoto = children
• njaa = hunger / hunger state
• ana njaa = he/she is hungry
• wana njaa = they are hungry
• baada ya = after
• kucheza = to play / to dance
• mpira = ball / football
• uwanja = field, ground, playground
• uwanjani = on/at the field

This sentence is especially useful because it teaches both vocabulary and important grammar patterns at the same time.