Nitawaona ninyi wote kesho asubuhi.

It breaks down as:

• ni- = I
• -ta- = future tense marker, will
• -wa- = object marker for you (plural) or them
• -on- = verb root see
• -a = final vowel

So Nitawaona literally has the structure I-will-you(pl)-see.

Because -wa- can be ambiguous: it can refer to you all or them, depending on context.

So in:

• Nitawaona = I will see you all / I will see them
• Nitawaona ninyi = clearly I will see you all

The separate pronoun ninyi is added for clarity or emphasis. Swahili often does this when the speaker wants to make the object especially clear.

Ninyi means you (plural), and wote means all.

Together, ninyi wote means all of you.

This is a very natural way to emphasize that the speaker means the whole group, not just some of them.

In Swahili, words like all agree with the noun or pronoun they describe.

Because ninyi refers to people in the wa- plural group, the matching form is wote.

Compare:

• mtu wote = every person / the whole person
• watu wote = all people
• ninyi wote = all of you

So wote is the agreement form that matches plural people.

Not always.

You could say:

• Nitawaona kesho asubuhi.

That can be understood from context. But by itself it may be ambiguous, because -wa- could mean you all or them.

Adding ninyi makes it explicit:

• Nitawaona ninyi kesho asubuhi. = I will see you all tomorrow morning.

Adding wote makes it even stronger:

• Nitawaona ninyi wote kesho asubuhi. = I will see all of you tomorrow morning.

Then you would use the singular object marker and pronoun:

• Nitakuona wewe kesho asubuhi. = I will see you tomorrow morning.

Breakdown:

• ni- = I
• -ta- = will
• -ku- = you (singular)
• -on- = see
• -a = final vowel

And:

• wewe = you (singular)

So the original sentence is definitely addressed to more than one person.

It means tomorrow morning.

• kesho = tomorrow
• asubuhi = morning

Swahili often places time expressions like this at the end of the sentence, but other placements are possible too, such as:

• Kesho asubuhi nitawaona ninyi wote.

That means the same thing.

Not completely. Swahili word order is fairly flexible, especially with time expressions.

All of these can work, depending on emphasis:

• Nitawaona ninyi wote kesho asubuhi.
• Kesho asubuhi nitawaona ninyi wote.
• Ninyi wote nitawaona kesho asubuhi.

The original version is natural and straightforward, with the time phrase placed at the end.

Because Swahili usually expresses tense inside the verb itself.

In English:

• I will see

In Swahili:

• ni-ta-ona
• literally I-will-see

So the future idea is carried by -ta-, not by a separate word.

Yes, you can say:

• Nitawaona wote kesho asubuhi.

That means I will see all of them / all of you tomorrow morning, depending on context.

But again, without ninyi, it is less explicit. The full version:

• Nitawaona ninyi wote kesho asubuhi

makes it very clear that the speaker means all of you.

It is basically neutral.

Nothing in it is especially formal or especially slangy. It would work in many normal situations.

What makes it slightly emphatic is the use of both:

• -wa- in the verb
• ninyi wote after the verb

That gives a sense of you all, every one of you.