Taa itawashwa mara moja.

Itawashwa can be broken down like this:

• i- = subject marker agreeing with taa
• -ta- = future tense, meaning will
• wash- = verb root from washa, meaning turn on / light
• -wa = passive ending

So itawashwa means it will be turned on.

Because taa belongs to a Swahili noun class that takes the subject marker i- in the singular.

English speakers often expect agreement based on natural gender or a separate word like it, but Swahili uses noun-class agreement. So:

• taa itawashwa = the light will be turned on

The i- is there because the verb must agree with taa.

In Swahili, tense is often built into the verb itself. Here, the future marker is -ta- inside itawashwa.

So instead of a separate word like English will, Swahili says it inside the verb:

• i-ta-washwa = it will be turned on

Yes. The ending -wa makes the verb passive.

That means the sentence focuses on the light as the thing receiving the action, not on the person doing it.

So:

• Taa itawashwa mara moja = The light will be turned on immediately

An active version would be something like:

• Watawasha taa mara moja = They will turn on the light immediately

Here mara moja means immediately, at once, or right away.

It is a very common expression in Swahili. Even though the individual words are:

• mara = time/occasion
• moja = one

the full phrase mara moja is normally understood as immediately in this kind of sentence.

Interestingly, taa often looks the same in both singular and plural. What changes is the agreement on the verb.

So:

• Taa itawashwa mara moja = The light will be turned on immediately
• Taa zitawashwa mara moja = The lights will be turned on immediately

Notice the verb changes from i- to zi- for plural agreement.

This is a very useful distinction:

• itawashwa = it will be turned on
• itawaka = it will be lit / it will shine / it will be on

-washa is a transitive idea: someone turns something on.
-waka is more intransitive: something is lit or burning.

So Taa itawashwa emphasizes the action of turning the light on, while Taa itawaka emphasizes the light being on or lit.

Yes, if the context already makes it clear what it refers to.

You could say:

• Itawashwa mara moja = It will be turned on immediately

But including taa makes the sentence clearer, especially for learners or when the topic has not been established yet.