Short Verbs with an Object Marker

Understanding when to drop ku- is crucial for building fluency in Swahili. It is a morphophonological rule (involving both grammar and sound rules) for short transitive verbs like -la (eat) and -nywa (drink).

The Rule:
In tenses that use the dummy ku- (such as the -na-, -li-, -ta-, -me-, and present conditional -nge- tenses), placing an object marker (OM) immediately before the root provides a syllable for stress, causing the ku- to drop.

• No OM: Ni-li-ku-la (I ate)
• With OM: Ni-li-ki-la (I ate it)

Tenses Without ku-:
It is important to note that some tenses never take the dummy ku- in the first place, regardless of object markers. These include the -ki- and -ka- tenses, as well as the subjunctive. (Note: While Standard Swahili drops ku- in these tenses, colloquial East African Swahili frequently retains it, e.g., nikikula or akakula).

Negative Tenses:
The dummy ku- behaves differently depending on the negative tense. In the present negative, ku- is dropped entirely (e.g., sili - I do not eat). However, in the future negative, the ku- is retained (e.g., sitakula - I will not eat).

Relative Infixes:
When using relative infixes (like -ye- or -cho-), the dummy ku- is retained (e.g., aliyekula - he who ate). This is because the verb's core macrostem (the object marker plus the root) must be at least two syllables long. Relative markers sit outside this core macrostem and do not count toward the minimum. If an object marker is added, it sits inside the macrostem, satisfying the rule, and the ku- drops (e.g., aliyekila - he who ate it).

Commands (Imperatives):
This rule also applies to commands. Monosyllabic verbs retain ku- in the basic singular imperative (e.g., Kula! - Eat!) and the plural imperative (e.g., Kuleni! - Eat, you all!), even though the plural form has enough syllables for stress. However, when an object marker is added, the ku- drops and the final vowel changes to -e (e.g., Kile! - Eat it! or Kileni! - Eat it, you all!).

Important Exceptions:
The ku- does not drop in the infinitive form (e.g., ku-ki-la, to eat it). Furthermore, do not confuse the dummy syllable with the past negative marker -ku-. In the standard past negative without an object marker (e.g., sikula - I did not eat), the dummy ku- actually drops; the visible ku is the past negative tense marker (si-ku-la). When an object marker is added, this tense marker -ku- remains (e.g., ha-ku-ki-la, he didn't eat it).

The Special Case of -pa (to give):
The verb -pa obligatorily requires an object marker for the recipient (usually animate, but it can be inanimate, like giving a school a book). Because the object marker is always present, -pa never uses the dummy ku- in finite conjugated tenses. However, in the infinitive form, the ku- is retained alongside the object marker (e.g., kumpa - to give him). Note that while a-li-ku-pa is a perfectly valid word, it means 'he gave you' (using the second-person object marker -ku-), not 'he gave' (with a dummy ku-).

Structural Ambiguity:
Because the object marker -ku- ('you') looks identical to the dummy ku-, a word like anakula can mean 'he is eating' (dummy ku- retained, no OM) OR 'he is eating you' (dummy ku- dropped, OM -ku- inserted). You must rely on context to tell them apart.

Not Yet:
Sijala means “I have not eaten yet,” with negative -ja- and the short stem -la. The stress-supporting ku- is absent even without an object marker. Compare sijakila (I have not eaten it yet, Class 7), where -ki- is the object marker.