Learn Hardcore Swahili: Chuo kikuu kimejenga maabara kubwa kwa ajili ya tafiti za sayansi. - The university has built a large laboratory for science research.

In Swahili the verb agrees with the noun class of its subject. Chuo kikuu (“university”) is class 7, so its subject concord is ki-. You then add the perfect tense marker -me- and the verb stem -jenga (“build”) to get kimejenga = ki- + -me- + jenga (“it has built”).

What does kwa ajili ya mean? Could I just say kwa?

Kwa ajili ya literally means “for the purpose of” (i.e. “for,” “in order to,” or “for the sake of”). It marks the purpose of the action:
maabara kubwa kwa ajili ya tafiti za sayansi
= “large laboratories for scientific research.”
Using only kwa (e.g. kwa tafiti) sounds abrupt or informal; kwa ajili ya is the standard way to express “for …” when stating a purpose.

Why is the genitive marker za used in tafiti za sayansi instead of ya?

Swahili uses different connectors based on noun class. Tafiti (“research”) here behaves like a class 6 (plural) noun, so it takes za as its “of” marker:
tafiti za sayansi = “research of science.”
If you had a class 5 noun (e.g. jiwe, “stone”), you would use la: jiwe la baridi (“stone of cold” = “cold stone”).

Why doesn’t the adjective kubwa agree with maabara (class 6) and become makubwa?

Strict grammar says class 6 adjectives should use ma- as the agreement prefix (maabara makubwa). However, common adjectives like kubwa (“big/large”), dogo (“small”), zuri (“good”), mbaya (“bad”) often appear in their root form without the prefix in everyday speech. Both maabara kubwa and maabara makubwa are understood; dropping the prefix is more colloquial.

What noun classes are chuo and maabara, and how can I tell?

• Chuo is class 7 (singular), its plural is vyuo (class 8). You can spot class 7 by the ch- prefix and plural vy-.
• Maabara is class 6 (plural of class 5), but because it’s a loanword it doesn’t use ji-/ma- in the singular; it appears only in the plural form maabara.

Could we use a different verb instead of jenga for “build,” like tengeneza or umba?

Yes, but nuances differ:
• jenga = physically erect or construct a building or structure.
• tengeneza = make or prepare something (machines, food, etc.).
• umba = shape or mold something (art, pottery).
For constructing a lab building, jenga is the most appropriate.

How would I turn the sentence into passive voice: “The laboratories have been built by the university”?

Use the passive suffix -wa, swap subject and object, and mark the agent with na:
Maabara (makubwa)
yamejengwa
na chuo kikuu
kwa ajili ya tafiti za sayansi.
Breakdown:
• yamejengwa = ya- (class 6 subject concord) + -me- (perfect) + jengwa (passive of jenga)
• na chuo kikuu = “by the university”
So you get:
Maabara makubwa yamejengwa na chuo kikuu kwa ajili ya tafiti za sayansi.