Anaongeza mwendo sasa.

Anaongeza can be broken down like this:

• a- = he/she
• -na- = present tense / ongoing action
• -ongeza = increase, add

So anaongeza means he/she is increasing or he/she increases, depending on context.

In Swahili, the subject is often built into the verb itself.

Here, a- already means he/she, so you do not need a separate pronoun.
That is very common in Swahili.

For example:

• Anaongeza = he/she is increasing
• Ninaongeza = I am increasing
• Tunaongeza = we are increasing

Mwendo literally relates to movement, motion, or pace. In this sentence, it most naturally means speed or pace.

So kuongeza mwendo means something like:

• to increase speed
• to pick up pace
• to speed up

Depending on context, mwendo can also refer more generally to movement or progress.

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

So mwendo can mean:

• speed
• the speed
• pace
• the pace

You understand the exact meaning from context rather than from an article.

Sasa means now. In Swahili, time words like this can often appear in different positions, but putting sasa at the end is very natural.

So these are all possible, though some may sound more natural depending on context:

• Anaongeza mwendo sasa.
• Sasa anaongeza mwendo.

The version with sasa at the end sounds straightforward and normal: He/she is increasing speed now.

Usually -na- marks a present or ongoing action. In many cases, it is similar to English is doing or are doing.

So anaongeza often means:

• he/she is increasing
• he/she is adding

In some contexts, it can also express a general present, but here with sasa, it clearly points to right now.

Yes, that is a very natural English translation.

Literally, it is more like He/she is increasing speed now, but in normal English, He/she is speeding up now is often the best way to say it.

So there is:

• a more literal sense: is increasing speed
• a more natural English sense: is speeding up

Yes. Kasi also means speed, and kuongeza kasi is a very common expression for to speed up.

There can be a slight nuance:

• mwendo = movement, pace, motion
• kasi = speed more directly

In many situations, both work, but kasi is especially common when talking about speed itself.

A simple pronunciation guide is:

• mwendo ≈ mwen-do
• sasa ≈ sa-sa
• anaongeza ≈ a-na-on-ge-za

A useful point: in mwendo, the mw is pronounced together at the start of the syllable, not as two completely separate words.

In Swahili, you can often make a yes/no question just by using question intonation.

So:

• Anaongeza mwendo sasa? = Is he/she increasing speed now?

You do not always need to change the word order the way English does.

If you wanted a negative form, it would be:

• Haongezi mwendo sasa. = He/she is not increasing speed now.