Wakati mwingine, mimi humsaidia shangazi kumimina unga kwenye sufuria kwa ajili ya vitumbua.

Literally, wakati mwingine is "another time" or "other time(s)":

• wakati = time / period
• mwingine = other / another

In practice, wakati mwingine is a very common way to say "sometimes" in Swahili.

So in this sentence, Wakati mwingine, mimi humsaidia… means "Sometimes, I help…", not “at another time I help…”. Context makes the meaning clear.

In Swahili:

• humsaidia already contains the idea of a subject, but the subject is not marked inside the verb when you use hu- (habitual). You normally add a noun or pronoun outside the verb:
  • Mimi humsaidia… – I (usually) help…
  • Yeye humsaidia… – He/She (usually) helps…

You cannot say ∗namsaidia with hu-; that would mix hu- and the normal subject marker na- (ni-na-m-saidia).

Compare:

• Mimi humsaidia shangazi… = Sometimes / usually / generally I help my aunt… (habitual action)
• Ninamsaidia shangazi… = I am helping my aunt / I help my aunt (now / these days) (present/ongoing or general).

In your sentence, mimi is used to clearly mark “I”, and hu- marks habitual action.

The prefix hu- marks a habitual or general action, something that happens regularly or typically, not just right now.

• Mimi humsaidia shangazi…
  = I usually / sometimes / generally help my aunt…

This hu- form:

• does not take a subject prefix (you don’t say ni-hu-msaidia),
• is often used with an explicit subject noun/pronoun before it (like mimi, yeye, watu, etc.).

Other examples:

• Watoto hucheza nje baada ya shule. – Children usually play outside after school.
• Yeye hulala mapema siku za kazi. – She/He normally sleeps early on workdays.

humsaidia can be broken down as:

• hu- – habitual marker
• -m- – object marker for class 1 (person) = her / him (here: my aunt)
• -saidia – verb root “help”

So humsaidia literally is:
(habitually) help-him/her → “(I/you/he/she) usually help(s) him/her.”

The subject (I/you/he/she) is understood from context or stated outside the verb (mimi, yeye, etc.) because hu- does not carry a subject prefix.

In Swahili, after verbs like kusaidia (to help), kutaka (to want), kupenda (to like), it is very common to use the infinitive (ku- + verb) to express “to do something”:

• kusaidia mtu kufanya kitu – to help someone to do something

So:

• humsaidia shangazi kumimina unga…
  = “(I) usually help aunt to pour the flour…”

Here:

• ku-mimina – to pour
• It links to humsaidia: help (her) to pour.

Using the infinitive ku- in this position is the normal Swahili pattern.

shangazi literally refers to your father’s sister in many Swahili-speaking cultures. Traditionally:

• shangazi – paternal aunt (father’s sister)
• mjomba – maternal uncle (mother’s brother)

However, in everyday usage:

• shangazi is often used more broadly for “aunt”, and can also be used respectfully for an older woman close to the family.

So in this sentence, shangazi is best understood simply as “(my) aunt”, unless the cultural distinction is important in context.

Both verbs involve pouring, but there is a nuance:

• kumimina – to pour out (often more controlled or careful, e.g. into a container, or in a stream)
• kumwaga – to pour / spill / dump, can sound less controlled; also used for “to spill” or “to throw out” (e.g. water, trash).

In the context of cooking:

• kumimina unga kwenye sufuria – to pour flour into the pot (controlled action, part of a recipe).

You could hear kumwaga unga, but that can also sound like “to spill / throw out flour”, depending on context. kumimina is very natural here.

unga generally means flour (maize flour, wheat flour, rice flour, etc.).

• In some contexts, people might say unga wa ugali and then casually refer to the cooked ugali itself, but strictly, unga is the dry flour.
• uji is porridge.

In kumimina unga kwenye sufuria, the natural reading is “to pour flour into the pot” (dry or batter mix, depending on recipe) as part of preparing vitumbua.

kwenye is a common preposition meaning in / into / at / on, depending on context.

• kwenye sufuria – in/into the pot

Yes, you can often replace kwenye with katika (more formal/neutral) or ndani ya (emphasizing inside):

• katika sufuria – in/into the pot
• ndani ya sufuria – inside the pot

All three can be correct; kwenye sufuria is very natural in everyday speech.

Literally:

• kwa ajili ya ≈ “for the sake of / for the purpose of”

In practice, it functions like “for” (with a purpose or beneficiary meaning):

• Nimeleta maua kwa ajili ya mama. – I brought flowers for (the sake of) mom.
• Tunajifunza kwa ajili ya mtihani. – We are studying for the exam.

In your sentence:

• kwa ajili ya vitumbua = “for the vitumbua” or “for making vitumbua”

So: pouring the flour into the pot for the purpose of preparing vitumbua.

vitumbua are small, usually round rice cakes/pancakes, often:

• made from rice (sometimes coconut),
• fried in a special pan with small round depressions,
• slightly sweet, often eaten for breakfast or as a snack.

Grammatically:

• singular: kitumbua
• plural: vitumbua

They belong to noun class 7/8 (ki-/vi-).

In Swahili (as in English), when you talk about making food items in a batch, you generally use the plural:

• You rarely make just one kitumbua.
• So you say kwa ajili ya vitumbua – “for (making) vitumbua (rice cakes)” in general.

Similarly:

• Ninapika maandazi. – I’m cooking maandazi (fried dough pieces).
• Tunafanya chapati. – We’re making chapatis.

The plural vitumbua reflects that you’re preparing several pieces, not a single cake.