Mtoto huyo alitumia ukanushi vibaya, lakini mwalimu alimsaidia kurekebisha sentensi.

Mtoto means child, and huyo is a demonstrative meaning that for a singular human noun.

So:

• mtoto = child
• huyo = that one / that person

Together, mtoto huyo means that child.

In Swahili, demonstratives usually come after the noun, not before it as in English.

Swahili has different demonstratives depending on distance and noun class.

For a singular person or animate noun like mtoto, you commonly get:

• huyu = this person / this child
• huyo = that person / that child
• yule = that person over there / that child over there

So huyo fits mtoto because mtoto is a class 1 singular noun, and the sentence is referring to that child rather than this child.

Alitumia can be broken down like this:

• a- = he/she
• -li- = past tense
• -tumi- = use
• -a = final vowel

So alitumia means he/she used.

A very important point for English speakers: Swahili verbs often pack the subject and tense directly into the verb, so you do not need a separate word for he or she.

It can mean either.

Swahili does not normally mark gender in verbs. So:

• alitumia = he used / she used

The same is true later in the sentence:

• alimsaidia = he/she helped him/her

You must get the gender from context, not from the verb form itself.

Ukanushi is a noun that refers to negation, negative wording, or sometimes denial, depending on context.

In a grammar-related sentence like this one, it most naturally means something like:

• negation
• a negative form
• the use of a negative construction

So the idea is that the child used negation incorrectly.

This noun comes from the verb kukanusha, which means to deny or to negate.

Vibaya means badly, wrongly, or incorrectly here.

It is functioning as an adverb, modifying the verb alitumia:

• alitumia vibaya = used incorrectly / used badly

English speakers often expect something closer to wrongly or incorrectly, and that is exactly how vibaya works in many contexts.

It is related to -baya, meaning bad.

Lakini means but.

It connects the two clauses:

• Mtoto huyo alitumia ukanushi vibaya
• lakini mwalimu alimsaidia kurekebisha sentensi

So it marks a contrast:

• the child made an error,
• but the teacher helped.

It works very much like English but.

Alimsaidia can be broken down like this:

• a- = he/she
• -li- = past tense
• -m- = him/her (object marker for a singular person)
• -saidi- = help
• -a = final vowel

So alimsaidia means he/she helped him/her.

This is a very useful Swahili pattern: the verb can include both the subject and the object.

The -m- refers back to mtoto huyo.

So:

• mwalimu = the teacher
• alimsaidia = helped him/her

That means the teacher helped the child.

This is a common Swahili feature: once a person has already been mentioned, the verb can carry an object marker referring back to that person.

Kurekebisha is the infinitive, meaning to correct, to fix, or to revise.

After kusaidia (to help), Swahili often uses an infinitive to express what someone is helped to do:

• kusaidia kufanya = help to do
• kusaidia kusoma = help to study/read
• kusaidia kurekebisha = help to correct

So:

• alimsaidia kurekebisha sentensi = helped him/her to correct the sentence

This is very similar to English help someone do something or help someone to do something.

Because Swahili can mark the object inside the verb.

In English, we say:

• the teacher helped him/her

In Swahili, the him/her part can be expressed by the object marker -m- in alimsaidia.

So a separate object pronoun is not necessary.

You could also hear fuller versions in some contexts, but the form in the sentence is completely natural.

Mwalimu means teacher, and it behaves like a class 1 singular noun, even though its form may not look exactly like simpler class 1 nouns.

Because it is a singular human noun, the verb agrees with it using the class 1 subject marker a-:

• mwalimu alimsaidia = the teacher helped him/her

Its plural is walimu = teachers.

Sentensi is a loanword meaning sentence.

Like many loanwords in Swahili, it may not show a very obvious noun-class prefix, but it is fully usable in normal Swahili.

In this sentence it is simply the object of kurekebisha:

• kurekebisha sentensi = to correct the sentence

Depending on context, speakers may also use other wording, but sentensi is common and easy to understand.

Yes. The original sentence is natural, but some near-equivalents are possible.

For example:

• Mtoto huyo alitumia ukanushi isivyofaa, lakini mwalimu alimsaidia kurekebisha sentensi.
• Mtoto huyo alitumia ukanushi kimakosa, lakini mwalimu alimsaidia kurekebisha sentensi.

These alternatives change the wording slightly, but the original version with vibaya is still perfectly understandable and natural.

The sentence has two coordinated clauses joined by lakini:

1. Mtoto huyo alitumia ukanushi vibaya
2. lakini mwalimu alimsaidia kurekebisha sentensi

A rough structure is:

• Subject + Verb + Object/Complement
• but
• Subject + Verb + Infinitive phrase

So this sentence is a good example of normal Swahili word order, with verbs carrying a lot of the grammatical information inside them.