Mchumba wa dada yangu alimwambia mpwa wetu asichafue kanga hiyo mpya.

Mchumba usually means fiancé or fiancée, and in some contexts it can also mean boyfriend/girlfriend or intended spouse.

The word itself is gender-neutral. Also, the subject marker a- in alimwambia can mean he or she. So this sentence does not tell you whether the fiancé(e) is male or female.

Wa is the connective/genitive link that means something like of.

So:

• mchumba wa dada yangu = the fiancé(e) of my sister
• in more natural English, my sister's fiancé(e)

The form wa is used because it agrees with mchumba, which is a singular human noun.

This is a very common learner question because dada refers to a person, but the possessive form is still yangu.

Certain nouns for people, especially family and relationship words like dada, kaka, mama, baba, and also words like rafiki, often use possessive forms such as:

• yangu = my
• yako = your
• yake = his/her

So dada yangu is the normal way to say my sister.

But these nouns still often behave like human nouns elsewhere, for example in verb agreement:

• Dada yangu alifika = My sister arrived

So this is one of those patterns you mostly learn as a set phrase: dada yangu.

Alimwambia can be divided like this:

• a- = he/she
• -li- = past tense
• -mw- = him/her
• -ambia = tell, say to

So alimwambia means he/she told him/her or he/she said to him/her.

The dictionary form is kuambia = to tell / to say to.

Because Swahili often uses an object marker on the verb even when the full object noun is also stated.

So in:

• alimwambia mpwa wetu

the -mw- already means him/her, and mpwa wetu then tells you exactly who that person is: our nephew/niece.

This is especially common when the object is:

• a person
• specific
• already known in the context

So this structure is completely normal.

Mpwa is a family term that can mean:

• nephew
• niece
• and in some contexts even grandchild

Like mchumba, it does not show gender by itself. So mpwa wetu could mean our nephew or our niece, depending on the context.

No. Wetu means our, not plural nephew/niece.

So:

• mpwa wetu = our nephew/niece (singular)
• wapwa wetu = our nephews/nieces (plural)

The plural meaning in wetu belongs to the owner (we/us), not to the noun mpwa itself.

Asichafue is a negative subjunctive form.

It comes from kuchafua = to dirty / stain / make dirty.

You can break it down like this:

• a- = he/she
• -si- = negative
• chafu-
• -e = subjunctive ending

So asichafue means:

• that he/she should not dirty
• not to dirty
• let him/her not dirty

After verbs like kuambia (to tell someone), Swahili often uses this kind of form for commands, instructions, or warnings.

Because the subjunctive in Swahili normally changes the final vowel to -e.

Compare:

• kuchafua = to dirty
• achafue = that he/she should dirty
• asichafue = that he/she should not dirty

So the -e is one of the clues that you are looking at a subjunctive form rather than a plain dictionary form.

It refers to mpwa wetu.

So the meaning is that the fiancé(e) told our nephew/niece not to dirty the kanga.

In other words:

• alimwambia mpwa wetu asichafue...
• he/she told our nephew/niece not to dirty...

If the person being told were plural, you would expect a plural subject marker in the subordinate verb.

Because Swahili often goes straight to the subjunctive after verbs like:

• kuambia = to tell
• kuomba = to ask/request
• kutaka = to want
• kushauri = to advise

So:

• alimwambia asichafue... = he/she told him/her not to dirty...

This is very natural. Swahili does not need an extra word like that here.

Because in Swahili, the noun usually comes first, and modifiers usually come after it.

So:

• kanga hiyo mpya

is literally:

• kanga + that + new

This is a normal Swahili word order. English usually puts some modifiers before the noun, but Swahili commonly puts them after it.

Swahili has a three-way distinction in demonstratives:

• hii = this
• hiyo = that (often near the listener, or already known/mentioned)
• ile = that over there / that more distant one

So kanga hiyo mpya means that new kanga.

Here, hiyo is the form that agrees with kanga and gives the sense of that rather than this.