Watoto wanacheza mchezo wa bodi sebuleni wakati wa mvua.

Watoto means children. Its singular form is mtoto, meaning child.

This is part of a very common Swahili pattern for people:

• mtoto = child
• watoto = children

So in this sentence, watoto tells you right away that the subject is plural.

Wanacheza is made of several parts combined into one word:

• wa- = they (used for plural human subjects)
• -na- = present time marker
• cheza = play

So:

wa- + -na- + cheza = wanacheza

This gives the meaning they are playing or sometimes they play, depending on context.

Usually, -na- in Swahili gives a present meaning. In many everyday contexts, wanacheza can mean either:

• they are playing
• they play

In this sentence, because it describes an action happening in a place and during a situation, English will usually translate it as are playing.

So the most natural understanding here is: The children are playing...

Swahili verbs must agree with the subject. Since watoto means children, the verb takes the plural human subject marker wa-.

Compare:

• Mtoto anacheza = The child is playing
• Watoto wanacheza = The children are playing

So wa- is there because the subject is plural and refers to people.

Because the sentence is talking about one game, not several games.

• mchezo = game
• michezo = games

So:

• wanacheza mchezo wa bodi = they are playing a board game
• wanacheza michezo ya bodi = they are playing board games

Even though children is plural, the object can still be singular if they are all playing one game together.

Literally, mchezo wa bodi means game of board. In natural English, that becomes board game.

Here:

• mchezo = game
• wa = a linking word often meaning of
• bodi = board

The wa is used because Swahili often links nouns this way instead of stacking them like English does.

So:

• English: board game
• Swahili: mchezo wa bodi

If the noun were plural, the connector would change:

• michezo ya bodi = board games

Sebuleni means in the living room or at the living room.

It comes from:

• sebule = living room / sitting room
• -ni = a locative ending meaning something like in, at, or to

So:

• sebule = living room
• sebuleni = in the living room

This is why Swahili does not need a separate word like English in here.

Wakati wa mvua literally means time of rain. In natural English, it usually means:

• during the rain
• when it is raining
• in rainy weather

Breaking it down:

• wakati = time
• wa = of
• mvua = rain

So the phrase is a natural Swahili way to express the time/situation in which the action is happening.

Swahili normally does not use articles like English the and a/an.

So:

• watoto can mean children or the children, depending on context
• mchezo can mean a game or the game, depending on context

English translations must choose the most natural option, but Swahili often leaves that unspecified unless the context makes it clear.

Yes, to some extent. The sentence as given uses a very normal order:

Watoto wanacheza mchezo wa bodi sebuleni wakati wa mvua.

That is basically: Subject + Verb + Object + Place + Time/Situation

This is a natural, neutral way to say it.

But Swahili can move parts around for emphasis. For example:

• Sebuleni, watoto wanacheza mchezo wa bodi wakati wa mvua. = In the living room, the children are playing a board game while it is raining.

The original version is a straightforward default sentence.

You would change both the noun and the verb agreement:

• Mtoto anacheza mchezo wa bodi sebuleni wakati wa mvua.

Changes:

• watoto → mtoto = child
• wanacheza → anacheza = he/she is playing

So the singular human subject marker is a-, while the plural human subject marker is wa-.