Tunapambana na tatizo hili.

Because Swahili usually packs several pieces of grammar into the verb itself.
Tunapambana can be broken down as:

• tu- = we
• -na- = present tense
• -pambana = fight / struggle

So instead of using separate words like English does, Swahili attaches them together into one verb form.

Tu- is the subject prefix meaning we.

In Swahili, the subject is often shown directly on the verb, so you do not need a separate word for we unless you want extra emphasis.

In Tunapambana, -na- is the present tense marker. It often corresponds to English are ...-ing or sometimes simple present, depending on context.

So tunapambana can mean things like:

• we are struggling
• we are fighting
• we struggle

The exact English translation depends on the situation.

-pambana is the verb stem. It commonly means fight, struggle, contend, or deal with in a difficult way.

With na, it often gives the idea of struggling against or dealing with something difficult.

The two na forms are different.

• In tu-na-pambana, -na- is a tense marker inside the verb.
• In pambana na tatizo hili, the separate na is a preposition.

That second na often means with, but after pambana it is often understood more like against, with, or in dealing with, depending on context.

Literally, na often means with. But with pambana, the whole expression pambana na usually means fight against, struggle with, or deal with.

So in this sentence, the idea is not friendly accompaniment like with a friend. It is more like confronting or dealing with a problem.

In normal Swahili word order, demonstratives like this usually come after the noun.

So:

• tatizo hili = this problem

That is the usual and natural order in Swahili.

Because hili has to agree with the noun class of tatizo.

Tatizo belongs to noun class 5 in the singular, and class 5 uses hili for this.

So:

• tatizo hili = this problem
• plural: matatizo haya = these problems

The form of this/these changes depending on the noun class.

Yes, you can. It is grammatically correct.

But in Swahili, sisi is usually unnecessary because tu- already means we. So:

• Tunapambana na tatizo hili = normal, natural
• Sisi tunapambana na tatizo hili = more emphasis, like We are the ones struggling with this problem

It can be both, depending on context.

The marker -na- is the normal present tense marker in Swahili, so it can cover:

• an action happening now: we are struggling
• a more general present situation: we struggle / we are dealing with

Context tells you which English version sounds best.

The negative form is:

Hatupambani na tatizo hili.

Here is the breakdown:

• hatu- = we do not / we are not
• pambani = negative present form of the verb

In the negative present, the final -a of the verb usually changes to -i.

The plural is:

matatizo haya

Here is the change:

• tatizo → matatizo = problem → problems
• hili → haya = this → these for that noun class

So if you wanted to say We are struggling with these problems, you would say:

Tunapambana na matatizo haya.