Mvua ililowesha shati langu jana jioni.

Because ililowesha contains both the subject marker and the past tense marker:

• i- = subject marker for mvua
• -li- = past tense
• -lowesha = wet / soak
• -a = final vowel

So ililowesha breaks down roughly as:

i-li-lowesh-a = it-past-wet-final vowel

In natural English, that gives the idea it wetted/soaked.

In Swahili, agreement is based on noun class, not just the first letter of the word.

Mvua belongs to noun class 9 in the singular, and class 9 nouns usually take the subject marker i-.

So:

• mvua → i-
• mvua ililowesha... = the rain wetted...

This is a very common thing for English speakers to get used to: the form of the word does not always tell you its class in an obvious way.

This is an important distinction:

• kulowa = to get wet / become wet
• kulowesha = to wet something / make something wet

So:

• Shati lililowa = The shirt got wet
• Mvua ililowesha shati = The rain wet the shirt

In this sentence, kulowesha is used because the verb has a direct object: shati langu.

In Swahili, the noun usually comes first, and possessives come after the noun.

So:

• shati langu = my shirt
• not langu shati

This is the normal order in Swahili:

• kitabu changu = my book
• rafiki yangu = my friend
• shati langu = my shirt

So English my shirt becomes Swahili shirt my in word order.

Because the possessive must agree with the noun class of shati.

Shati is a class 5 noun in the singular, and class 5 uses the possessive agreement la- with the possessive stem -angu.

So:

• la + angu → langu

Compare:

• shati langu = my shirt
• gari langu = my car
• nyumba yangu = my house
  (different noun class, so different agreement)
• kitabu changu = my book
  (again, different noun class)

So langu is not random; it is there because shati requires that agreement pattern.

Because Swahili does not have articles like English a / an / the.

Whether something is understood as the rain, rain, the shirt, or my shirt depends on context and on other words in the sentence.

Here:

• mvua can mean rain / the rain
• shati langu already means my shirt, so that is specific even without an article

This is very normal in Swahili.

Swahili often uses time expressions directly, without a preposition.

So:

• jana = yesterday
• jioni = evening
• jana jioni = yesterday evening

You do not need a separate word for in here.

This is similar to other Swahili time expressions:

• leo = today
• kesho = tomorrow
• asubuhi = in the morning / morning
• usiku = at night / night

So jana jioni is a natural adverbial time phrase.

Yes. The basic order here is very normal:

Subject + Verb + Object + Time

So:

• Mvua = subject
• ililowesha = verb
• shati langu = object
• jana jioni = time expression

That makes the structure very straightforward for learners:

Mvua ililowesha shati langu jana jioni.

Swahili is often quite comfortable with this kind of SVO order.

Yes. A passive version would be:

Shati langu lililoweshwa na mvua jana jioni.

Breakdown:

• shati langu = my shirt
• lililoweshwa = was wetted/soaked
• na mvua = by the rain
• jana jioni = yesterday evening

So the active sentence focuses on the rain as the subject, while the passive sentence focuses on the shirt.

A simple pronunciation guide:

• Mvua → m-VU-a
• ililowesha → i-li-lo-WE-sha
• shati → SHA-ti
• langu → LA-ngoo
• jana → JA-na
• jioni → ji-O-ni

A few helpful notes:

• Swahili vowels are usually pronounced clearly:
  a, e, i, o, u
• jioni has three vowel sounds: ji-o-ni
• sh sounds like English sh in shoe

Swahili pronunciation is generally much more regular than English spelling.

It can often mean either wet or soak, depending on context.

So Mvua ililowesha shati langu could be understood as:

• The rain wet my shirt
• The rain soaked my shirt

If the context suggests the shirt became very wet, soaked may sound more natural in English. If the context is lighter or more neutral, wet works well.

So the Swahili verb is flexible, and English chooses the best wording from context.