The Causative Extension

In English, you can take a basic verb and extend its meaning in a number of ways. For example, if you use “make” plus the basic verb, as in “make return” from “return,” you have what’s called the causative. That name isn’t surprising, because if you make someone return, you’re causing him or her to return. Swahili has a special way of extending the meaning of basic verbs, by adding suffixes called extensions, and one of these extensions gives you the causative. To take our English example and apply it to Swahili, kurudi means “to return,” and by changing the ending to –isha, you have kurudisha, which means “to make return,” “to cause to return,” or “to bring back.” There are a few different forms of the causative extension, but the characteristic consonant is –sh– or –z–.

1. Take off the final vowel on the infinitive, and if the nearest remaining vowel is a, i, or u, then the causative extension takes the form –isha:

kurudi (to return) = kurudisha	kurudisha (to cause to return, bring back)
Ali anarudisha vitabu.	Ali is bringing back the books.
kuzama (to drown) = kuzamisha	kuzamisha (to cause to drown, sink)
Upepo umezamisha meli.	The storm caused the ship to sink.

2. If the nearest remaining vowel is e or o, then the causative extension takes the form –esha:

kusoma (to read, to study) = kusomesha	kusomesha (to cause to study, teach)
Mwalimu huyu anafundisha Kiswahili.	This teacher teaches Swahili.
kukopa (to borrow) = kukopesha	kukopesha (to make borrow, lend)
Nimemkopesha Ali pesa.	I have lent Ali some money.

3. Most verbs whose root forms end in –k undergo a slight modification when the causative extension is added. The –k changes to –sh, and no further syllable is added:

kukumbuka (to remember)	kukumbusha (to make remember, remind)
Picha hii inanikumbusha zamani.	This picture reminds me of the past.
kuwaka (to burn, be on fire)	kuwasha (to light on fire)
Nani amewasha majani?	Who has set the leaves on fire?

Note that the common verbs kuandika (to write) and kucheka (to laugh) are exceptions to this rule. Their causative forms are kuandikisha (to register) and kuchekesha (to make laugh, to amuse).

4. Some verbs insert a –z– in their causative forms, while the verb kulala changes its last consonant to –z. Also, if a verb root ends in –n, the causative is formed with –ny–:

kuuma (to hurt, to be painful)	kuumiza (to hurt, to cause pain)
Viatu vyangu vinaniumiza.	My shoes are hurting me.
kulala (to sleep)	kulaza (to cause to sleep, to put to bed)
Dawa zinalaza.	The drugs make you sleepy.
kupona (to get better, recover)	kuponya (to make better, to cure)
Dawa hii inaponya malaria?	Does this medicine cure malaria?

5. You can also form causative verbs from adjectives and nouns. Simply take off the final vowel, and add –isha if the nearest remaining vowel is a, i, or u, and –esha if the nearest remaining vowel is –o or –e.

–safi (clean)	kusafisha (to clean)
bora (good, better)	kuboresha (to make better, to improve)
rahisi (easy)	kurahisisha (to simplify)
maana (meaning)	kumaanisha (to mean)
sababu (reason, cause)	kusababisha (to cause)
Neno hili linamaanisha nini?	What does this word mean?
Paa alisababisha ajali.	The deer caused an accident.