Nguzo zikisimama vizuri, nyumba itakuwa imara.

It breaks down like this:

• zi- = the subject marker agreeing with nguzo
• -ki- = if/when
• simama = stand, be upright

So zikisimama means if they stand or when they stand.

In this sentence, with nguzo, it has the sense of if the pillars stand properly / are properly set upright.

Because nguzo belongs to a noun class where the singular and plural often have the same form.

So:

• nguzo can mean pillar
• nguzo can also mean pillars

You tell the difference from agreement elsewhere in the sentence. Here, zi- in zikisimama shows that nguzo is plural, so it means pillars.

Swahili verbs must agree with the noun class of their subject.

Here, nguzo is plural, so the verb takes the plural agreement marker zi-.

That is why you get:

• nguzo zikisimama = if the pillars stand

If it were singular, you would expect i- instead:

• nguzo ikisimama = if the pillar stands

Because Swahili often builds the idea of if directly into the verb.

In this sentence, -ki- carries the meaning if or when. So instead of using a separate word, Swahili packs that meaning into zikisimama.

This is very common and natural in Swahili.

It can mean either, depending on context.

In a sentence like this, -ki- often has a broad sense such as:

• if
• when
• whenever

So this sentence could be understood as:

• If the pillars stand properly, the house will be strong
• When the pillars are properly set, the house will be strong

Both fit the Swahili structure.

Vizuri means well, properly, or in a good way.

Here it describes how the pillars stand. So it does not just mean that they are standing, but that they are standing properly, firmly, or correctly.

So:

• zikisimama vizuri = if they stand well / properly

It is made of three parts:

• i- = subject marker for nyumba
• -ta- = future tense
• kuwa = be

So:

• itakuwa = it will be

That gives:

• nyumba itakuwa imara = the house will be strong / stable

Like nguzo, nyumba can have the same form in singular and plural.

Again, agreement tells you the number.

Here the verb is itakuwa, with i-, which shows singular agreement. So in this sentence nyumba means house, not houses.

If it were plural, you would expect:

• nyumba zitakuwa imara = the houses will be strong

Imara is commonly used as an adjective meaning strong, firm, or stable, and it often stays in the same form.

So in:

• nyumba itakuwa imara

imara works as the description strong/stable without needing a visible change.

A natural translation is:

• the house will be strong
• the house will be stable

Basically yes, but with objects like pillars it has a more specific practical sense.

For people, simama is often just stand up or stand.

For things like pillars, it can mean:

• stand upright
• remain standing
• be properly erected
• be set firmly

So in good English, this sentence may sound more natural as:

• If the pillars are properly set, the house will be strong

not only the more literal:

• If the pillars stand well, the house will be strong