Learn Hardcore Swahili: Chakula tulichopika leo ni kitamu kuliko chakula tulichopika wiki iliyopita. - The food that we cooked today is tastier than the food that we cooked last week.

So tulichopika literally means “we cooked which” → “which we cooked”.
It’s a verb form that already contains the idea of “the food that we cooked”.

Why is it tulichopika and not just tulipika?

Tulipika = we cooked (simple past, no relative idea).

In chakula tulichopika, the verb needs to mean “that we cooked”, not just “we cooked”.
To express “that/which” as part of the verb in Swahili, you add a relative marker:

tuli-pika → “we cooked”
tuli-cho-pika → “we cooked which / which we cooked”

So chakula tulichopika = “the food that we cooked”.
Without -cho-, it would sound incomplete or wrong as a relative clause.

What exactly does the -cho- in tulichopika refer to?

The -cho- is a relative marker that refers back to chakula:

chakula is in noun class 7 (ki-/vi-)
relative marker for class 7 is -cho- (singular), -vyo- (plural)

Because chakula is the thing being cooked (the object), the verb takes the matching relative marker:

chakula tulichopika → literally “the food we-PAST-CHO-cooked” → “the food which we cooked”.

If the head noun were from another class, the relative marker would change, e.g.:

mtu tuliyemwona (person we saw) – class 1, relative -ye-
wiki tuliyoisahau (the week we forgot) – class 9, relative -yo-

Why is the past tense -li- used with leo (today)? Doesn’t that mean “we cooked” in the past?

Yes, -li- is the simple past, meaning the action is finished.
Adding leo tells you when that past action happened: earlier today.

So:

tulichopika leo = “that we cooked today (earlier today, already finished)”
If you said tunachopika leo, it would mean “that we are cooking today” (ongoing or planned today).

Using -li- with leo is natural when the cooking is already done at some time today.

Why is it chakula tulichopika leo and not leo tulichopika chakula or something similar?

In Swahili relative clauses, the normal pattern is:

[head noun] + [relative verb phrase + other info]

So:

chakula tulichopika leo
= the food [that we cooked today]
(head noun chakula, followed by the relative clause tulichopika leo)

Time words like leo usually come after the verb they modify, inside the clause:

tulichopika leo (we cooked today)
tulichopika jana (we cooked yesterday)

You can move leo around a bit for emphasis (e.g. leo tumepika chakula kitamu), but in a relative structure like this, chakula tulichopika leo is the most natural ordering.

Why is it kitamu and not just tamu?

Tamu is the adjective root meaning sweet / tasty.
In Swahili, adjectives usually agree with the noun class.

chakula is class 7 (ki-/vi-)
class 7 adjective form takes the prefix ki-

So:

chakula kitamu = tasty food
chakula hiki ni kitamu = this food is tasty

In the sentence:

Chakula tulichopika leo ni kitamu...

kitamu agrees with chakula.
You might hear bare tamu in some casual speech, but kitamu is the grammatically regular form here.

How does kuliko work in this comparison?

Kuliko is the usual word for “than” in comparisons:

X ni kitamu kuliko Y = X is tastier than Y

In this sentence:

Chakula tulichopika leo ni kitamu kuliko chakula tulichopika wiki iliyopita.

The structure is:

[Subject]: Chakula tulichopika leo
[Copula + adjective]: ni kitamu
[Comparator]: kuliko chakula tulichopika wiki iliyopita

So it literally means:
“The food we cooked today is tasty than the food we cooked last week.”

You can also sometimes drop the repeated noun after kuliko if it’s obvious:

…ni kitamu kuliko tulichopika wiki iliyopita. (informal but common)

What does wiki iliyopita literally mean and how is iliyopita formed?

Wiki iliyopita literally means “the week that passed” → “last week”.

Iliyopita comes from the verb pita (to pass) plus relative and tense marking:

i- = class 9 subject/relative prefix (agreeing with wiki)
-li- = past/perfect aspect
-yo- / -o- (historically, relative element) + pita

Together, it functions like an adjective describing wiki:

wiki iliyopita = the week that passed → last week
mwaka uliopita = the year that passed → last year

You don’t need an extra word for “last”; iliyopita already expresses that idea.

Why isn’t there an object pronoun like ki- in tulichopika for chakula?

In chakula tulichopika, chakula is the head noun of the relative clause, not just any object.
The reference to chakula is made through the relative marker -cho-, not an ordinary object prefix.

Compare:

Tulikikipika chakula. = We cooked it (the food).
- ki- is a normal object marker for class 7.
Chakula tulichokipika… would be odd, because the noun is already there as the head of the relative clause.

In a relative clause like chakula tulichopika:

the noun is explicitly stated (chakula)
and the verb carries the relative marker (-cho-) that connects back to it
you don’t normally also add a separate object pronoun.

What is the difference between chakula tulichopika and chakula ambacho tulipika?

Both mean “the food that we cooked”, but the structure is different:

Chakula tulichopika
- relative meaning is built inside the verb with -cho-
- very common and natural in everyday Swahili
Chakula ambacho tulipika
- uses the relative pronoun ambacho (class 7 form of amba-)
- verb is simple past tulipika (no relative marker)
- sounds a bit more explicit/formal or “bookish”

Both are correct.
In speech, the form chakula tulichopika is more common and more compact.

Can the sentence be said more simply without relative clauses?

Yes, you can express the same idea in simpler sentences, for example:

Chakula tulichopika leo ni kitamu sana. Chakula tulichopika wiki iliyopita hakikuwa kitamu sana.
→ The food we cooked today is very tasty. The food we cooked last week was not very tasty.

Or, even more basic:

Chakula cha leo ni kitamu kuliko cha wiki iliyopita.

Here cha leo / cha wiki iliyopita = “today’s / last week’s” (using cha as an associative).

The original sentence is more compact and expressive, but for beginners, these simpler patterns are often easier to produce.

Can leo and wiki iliyopita move to other positions in the sentence?

There is some flexibility, but not every position sounds natural.

Most natural:

Chakula tulichopika leo ni kitamu kuliko chakula tulichopika wiki iliyopita.

Possible variations, with slightly different emphasis:

Leo tumepika chakula kitamu kuliko chakula tulichopika wiki iliyopita.
Chakula tulichopika leo ni kitamu kuliko chakula tulichopika wiki iliyopita leo. (this last leo would normally be unnecessary/confusing)

Inside each clause, time words usually come after the verb they relate to:

tulichopika leo
tulichopika wiki iliyopita

Putting leo before chakula in this exact relative structure (Leo chakula tulichopika…) would sound awkward in standard Swahili.

Is ni necessary in ni kitamu, or could we say Chakula tulichopika leo kitamu kuliko…?

In standard Swahili, the copula ni is normally used:

Chakula tulichopika leo ni kitamu…

You will sometimes hear ni dropped in casual speech:

Chakula hiki kitamu sana.

However, in a full, careful sentence like the one you’re learning, it’s better (and more correct for learners) to keep ni:

Chakula tulichopika leo ni kitamu kuliko chakula tulichopika wiki iliyopita.