Ni baada ya kufika kwenye maporomoko ya maji ndipo tulipiga picha.

This is an emphatic structure. It highlights the time phrase baada ya kufika kwenye maporomoko ya maji.

So instead of just saying:

Tulipiga picha baada ya kufika kwenye maporomoko ya maji.
= We took pictures after arriving at the waterfall.

the sentence says:

Ni baada ya kufika kwenye maporomoko ya maji ndipo tulipiga picha.

This is closer to:

It was after arriving at the waterfall that we took pictures.

So ni ... ndipo adds focus or emphasis, especially on when something happened.

Not exactly in the normal sense of is.

You may already know ni as a copula, like Yeye ni mwalimu = He/She is a teacher.
But in this sentence, ni helps form a focus/emphasis pattern: ni ... ndipo.

So here it is better understood as part of the structure it is/it was ... that ..., rather than a simple standalone is.

In this sentence, ndipo helps introduce the main clause after the focused part.

In the pattern ni X ndipo Y, it often means something like:

• it is X that Y
• it was then/there that
• that is when

So:

Ni baada ya kufika ... ndipo tulipiga picha
= It was after arriving ... that we took pictures

On its own in other contexts, ndipo can also mean something like then or that’s when, but here it is mainly functioning as part of this emphasis structure.

Because baada ya is the normal expression for after when followed by a noun or an infinitive.

• baada ya chakula = after food / after the meal
• baada ya kazi = after work
• baada ya kufika = after arriving

The ku- form of the verb works like to arrive / arriving, so baada ya kufika literally means after arriving.

Kufika is the infinitive form of the verb -fika, meaning to arrive or to reach.

Breakdown:

• ku- = infinitive marker, like to
• -fika = verb root, arrive/reach

So:

• kufika = to arrive
• baada ya kufika = after arriving

Kwenye is a locative word meaning something like:

• at
• in
• on
• sometimes to

The exact translation depends on context.

Here, with kufika (to arrive), it gives the destination/location:

kwenye maporomoko ya maji
= at the waterfall / to the waterfall area

So a natural understanding is after arriving at the waterfall.

Yes, very literally it looks like falls/cascades of water.

This is a normal Swahili expression for waterfall or waterfalls:

• maporomoko = falls, cascades, plunges
• ya maji = of water

So maporomoko ya maji is just the standard way to refer to a waterfall/waterfalls.

Even if English often uses singular waterfall, Swahili may use this plural-looking form naturally.

Ya is a connector meaning of, and it agrees with the noun class of maporomoko.

So:

• maporomoko ya maji = falls of water

This kind of connector is very common in Swahili:

• kitabu cha mwanafunzi = the student’s book / book of the student
• mlango wa nyumba = door of the house
• maporomoko ya maji = waterfalls / waterfall

So ya is not random; it is the agreement form required by the noun class of maporomoko.

Tulipiga breaks down like this:

• tu- = we
• -li- = past tense
• -piga = verb root hit/strike

So literally it is we hit in the past.

But in Swahili, kupiga picha is an idiomatic expression meaning to take pictures or to take a photo.

So:

• tulipiga picha = we took pictures

Yes, -piga often does mean hit, strike, or beat. But like many verbs in many languages, it appears in idiomatic expressions with extended meanings.

For example, kupiga picha is the normal way to say:

• take a photo
• take pictures

So you should learn kupiga picha as a set phrase, not translate it word-for-word every time.

Because picha often stays the same in both singular and plural.

So:

• picha can mean a picture
• picha can also mean pictures

The context tells you which is meant.

That means:

• nilipiga picha can mean I took a picture or I took pictures
• tulipiga picha can mean we took a picture or we took pictures

Yes. A more straightforward version would be:

Tulipiga picha baada ya kufika kwenye maporomoko ya maji.

That simply means:

We took pictures after arriving at the waterfall.

The original sentence is more marked and more emphatic because of ni ... ndipo. It draws attention to the fact that the picture-taking happened after arrival.

Yes, slightly. The sentence puts the time phrase first for emphasis.

Normal, neutral order:

Tulipiga picha baada ya kufika kwenye maporomoko ya maji.

Emphatic order:

Ni baada ya kufika kwenye maporomoko ya maji ndipo tulipiga picha.

So the order is unusual only because the speaker wants to focus on after arriving at the waterfall.

Yes, that is a very useful way to think about it.

In English, a cleft sentence is something like:

It was after we arrived at the waterfall that we took pictures.

This Swahili sentence works in a very similar way:

Ni baada ya kufika kwenye maporomoko ya maji ndipo tulipiga picha.

So if you know English cleft sentences, this is a good comparison.