Chura wale wanaweza kuwa marafiki wa bustani, kwa sababu wanakula wadudu wabaya.

In Swahili, some nouns do not change form between singular and plural. Chura can mean frog or frogs.

You know it is plural here because of the other words that agree with it:

• wale = those
• wanaweza = they can
• wanakula = they eat

So the agreement words show that chura is plural in this sentence.

Wale means those.

Swahili demonstratives usually come after the noun, not before it. So:

• chura wale = those frogs

It also helps show that the noun is plural and refers to a specific group of frogs.

The wa- is the subject prefix for they when the subject is plural and animate.

So:

• wa-na-weza = they can
• wa-na-kula = they eat

Swahili verbs normally include a subject marker, so you do not need a separate word for they.

-na- is the common present tense marker.

So:

• wanaweza = they can / they are able to
• wanakula = they eat / they are eating

In many contexts, this tense can sound either habitual or present, depending on the sentence.

Kuwa means to be.

After -weza (can / be able to), Swahili normally uses an infinitive:

• wanaweza kuwa = they can be

So:

• wanaweza kuwa marafiki = they can be friends

You cannot normally leave out kuwa here.

Literally, it means friends of the garden.

In natural English, that can be understood as:

• garden friends
• friends to the garden
• good for the garden

The idea is that the frogs are beneficial in a garden.

The linking word here is the associative marker -a, which changes form to match the noun before it.

With plural animate nouns such as marafiki, it appears as wa:

• marafiki wa bustani = friends of the garden

So wa here is not the same as the subject prefix wa- in the verbs, even though they look alike.

In Swahili, adjectives usually come after the noun they describe.

So:

• wadudu wabaya = bad insects

Also, the adjective agrees with the noun, which is why both begin with wa- here.

Literally, wabaya means bad.

But in this sentence, wadudu wabaya is better understood as harmful insects or even pests, because the idea is that these insects are bad for the garden.

So the literal meaning is bad insects, but the natural meaning in context is closer to harmful bugs/pests.

Kwa sababu means because.

It introduces the reason:

• kwa sababu wanakula wadudu wabaya
• because they eat harmful insects

It is a very common and useful expression in Swahili.

Yes. This is a very normal structure.

The sentence is roughly:

• Chura wale = subject
• wanaweza kuwa marafiki wa bustani = main statement
• kwa sababu wanakula wadudu wabaya = reason clause

So the overall order is very natural and clear: Those frogs can be friends of the garden, because they eat harmful insects.

Yes. In a sentence like this, wanakula is most naturally understood as a general fact:

• they eat harmful insects

It does not have to mean the frogs are eating them at this exact moment. In context, it describes what frogs generally do, which is why it explains why they are helpful in the garden.