Learn Hardcore Swahili: Wakati tunapanga ratiba pamoja, kila mmoja wetu anajua majukumu yake yote. - When we plan the schedule together, each of us knows all of his or her responsibilities.

Wakati literally means “time”.
In this sentence, Wakati tunapanga ratiba pamoja… means “When we plan the schedule together…” or “While we are planning the schedule together…”.

It can express both “when(ever)” and “while”, depending on context.
Often it introduces a time clause, like English when/while.

How is tunapanga formed, and what tense/aspect does it express?

Tunapanga comes from:

tu- = subject prefix for “we”
-na- = present tense marker (general present / habitual / current)
panga = verb stem “arrange, plan, organize”

So tunapanga means “we are planning” or “we (usually) plan”.
In this sentence it’s a general/habitual present: whenever we plan the schedule…

Could you use tunapopanga instead of tunapanga after wakati?

Yes, you can say:

Wakati tunapopanga ratiba pamoja…

Here -po- is a relative/locative marker meaning roughly “when/at the time that”.
Both are acceptable:

Wakati tunapanga ratiba pamoja…
Tunapopanga ratiba pamoja…

The version with -po- (tunapopanga) sounds a bit more explicitly like “whenever we are planning”, but the meaning is very close.

What exactly does ratiba mean, and what noun class is it?

Ratiba means “schedule, timetable, program (of events)”.

It is usually treated as a class 9/10 noun (N-class), like safari / safari, siku / siku.
In practice, you will most often see it in the singular, because “the schedule” is usually thought of as one thing.

Examples:

Ratiba ya kazi – work schedule
Ratiba ya masomo – class timetable

What does pamoja add here, and how is it different from kwa pamoja?

Pamoja means “together”.

Tunapanga ratiba pamoja – we plan the schedule together.
Kwa pamoja literally “in togetherness,” often also translated as “together / jointly / collectively”.

Both are fine:

Tunapanga ratiba pamoja
Tunapanga ratiba kwa pamoja

Kwa pamoja can sound slightly more formal or emphatic about everyone’s joint action.

How should I understand kila mmoja wetu?

Kila mmoja wetu breaks down as:

kila = each / every
mmoja (from m- + moja) = one (person) in noun class 1
wetu = “our / of us”

So kila mmoja wetu literally means “each one of us”.
Note: After kila, the following noun is singular, even though the overall idea is plural (many people treated one by one).

Why is it anajua (he/she knows) and not wanajua (they know), since we are talking about all of us?

The grammatical subject here is kila mmoja wetu = each one of us, which is singular in Swahili.
So the verb agrees with that singular subject:

kila mmoja wetu anajua – each one of us knows
watu wote wanajua – all the people know (here the subject is clearly plural)

In Swahili, verb agreement follows the grammar (singular “each one”), not the “logical” plurality of the whole group.

What does majukumu mean, and what is its singular form?

Majukumu means “responsibilities, duties, tasks, obligations”.

Singular: jukumu – a responsibility / a duty
Plural: majukumu – class 5/6 noun: jukumu / majukumu

In the sentence, majukumu yake yote = “all of his/her responsibilities.”

Why is it yake and not yao or yetu in majukumu yake yote?

Yake is the possessive for “his / her / its” (3rd person singular), agreeing with a noun in the ma- (class 6):

majukumu yake – his/her responsibilities

If you changed the owner, you’d change the possessive, but it must still agree with ma-:

majukumu yangu – my responsibilities
majukumu yako – your responsibilities (sg.)
majukumu yetu – our responsibilities
majukumu yenu – your responsibilities (pl.)
majukumu yao – their responsibilities

Here we’re talking about each person’s own duties, so yake is correct (each one’s responsibilities).

Does yake distinguish between “his” and “her”?

No. Swahili does not mark natural gender in pronouns like English does.

yake can mean “his”, “her”, or “its”, depending on context.
So majukumu yake yote could be “all his responsibilities” or “all her responsibilities.”

Why is yote at the end, and what does it agree with?

Yote means “all” and is placed after the noun + possessive:

majukumu yake yote – all of his/her responsibilities

It agrees with majukumu, which is class 6 (ma-) plural.
For class 6, “all” is yote:

majibu yote – all the answers
maji yote – all the water
majukumu yake yote – all his/her responsibilities

Word order is typically: noun + possessive + “all”.

Could I say majukumu yote yake instead of majukumu yake yote?

While majukumu yote yake would likely still be understood, the natural and standard order is:

majukumu yake yote

The common pattern is:

[noun] + [possessive] + [quantity word like yote, wote, zote, etc.]

So it’s better to stick with majukumu yake yote.

Is this sentence talking about one specific occasion or about what usually happens?

With tunapanga and anajua in the present/habitual sense, the sentence naturally means what usually happens:

“When(ever) we plan the schedule together, each one of us knows all his/her responsibilities.”

Context could make it feel like a one-time situation, but grammatically it leans toward a general rule or repeated habit.

Can I replace kila mmoja wetu with kila mtu or kila mmoja and keep the same meaning?

Yes, with small nuance differences:

kila mtu anajua majukumu yake yote – each person knows all his/her responsibilities (general)
kila mmoja anajua majukumu yake yote – each one knows all his/her responsibilities (context must already tell you which group)
kila mmoja wetu anajua majukumu yake yote – each one of us knows all his/her responsibilities (specifically referring to our group)

The original clearly limits the statement to “us.”