Nitumie ujumbe kesho.

Nitumie comes from the verb -tuma = to send.

In nitumie:

• ni- = me
• tum = the verb root from -tuma
• -ie / -e = the ending used here for a request/command form

So nitumie means send me.

This is a very common pattern in Swahili when giving a command that includes an object like me, him/her, us, etc.

Tuma is the basic imperative: Send!

But when you add an object marker like ni- (me), Swahili normally uses the subjunctive-style ending -e in commands:

• Tuma = send!
• Nitumie = send me!

So the -e ending is expected here because the command includes me.

It is not stated separately, because Swahili commands usually do not need a subject word.

In English, we say Send me a message tomorrow, and the you is understood.
Swahili works the same way here:

• Nitumie ujumbe kesho. = Send me a message tomorrow.

So the person being spoken to is understood from the command form.

Swahili does not use articles like English a, an, and the.

So:

• ujumbe can mean a message, the message, or just message

The exact meaning depends on context. In this sentence, the natural English translation is usually a message.

Ujumbe means message.

It can refer to:

• a text message
• a written message
• a verbal message
• a general communication

In modern everyday use, it is very natural for things like phone or chat messages too.

Kesho means tomorrow.

It tells you when the action should happen:

• Nitumie ujumbe kesho. = Send me a message tomorrow.

It is an adverb of time, and in this sentence it comes at the end, which is very normal in Swahili.

Yes, Swahili word order is fairly flexible, especially with time expressions.

For example, these are possible:

• Nitumie ujumbe kesho.
• Kesho nitumie ujumbe.

Both are understandable. The first one is a very neutral, natural order.
Putting kesho first gives it a little more emphasis: Tomorrow, send me a message.

By itself, nitumie ujumbe kesho is a straightforward command/request. Whether it feels polite depends on context and your relationship with the person.

If you want to sound softer or more polite, you can add tafadhali = please:

• Tafadhali, nitumie ujumbe kesho. = Please send me a message tomorrow.

So the basic sentence is fine, but politeness can be increased with extra words.

To address more than one person, Swahili often adds -ni to the imperative form.

So you can say:

• Nitumieni ujumbe kesho. = Send me a message tomorrow. / Send me messages tomorrow. (to you all)

Here, the speaker is talking to multiple people instead of just one.

Because in Swahili, object markers are usually attached directly to the verb.

So ni- (me) joins with the verb form:

• nitumie = one word

This is very typical of Swahili verbs. A lot of grammatical information gets built into one verb word.

Yes, depending on context, it could.

Because ujumbe has no article, it can sometimes be understood as:

• a message
• the message

If the speaker and listener already know which message is meant, English might translate it as the message.
If not, a message is usually the most natural translation.

Mainly because of kesho and the fact that this is a command/request.

The form nitumie itself is not a regular future tense like I will...
Instead, it is a command/request form: send me.

The time word kesho makes it clear that the action should happen tomorrow.