-ku- (yambwa)

Because -ku- refers to a person, it is grammatically mandatory. You cannot just use the independent pronoun wewe and skip the object marker. Note that -ku- is strictly for the singular "you"; for the plural "you all" (nyinyi), you can use the object marker -wa-, which is the shared object marker for all plural animate objects (meaning both "them" and "you all"). To clarify that you mean "you all" rather than "them", speakers often add the independent pronoun (e.g., nitawaona nyinyi) or attach the plural suffix -ni to the verb, changing the final -a to -e- before adding it (e.g., nitawaoneni). Alternatively, Standard Swahili also allows using the singular object marker -ku- combined with the plural suffix -ni (e.g., nitakuoneni) to address a plural "you".

Important Rules:

• Monosyllabic Verbs: Short verbs like -la (eat) or -nywa (drink) usually need a "dummy" infinitive ku- to sound right (e.g., ninakula). However, when you add an object marker to a conjugated verb, this infinitive ku- is strictly dropped in Standard Swahili. So, "The lion will eat you" is simba atakula, not *atakukula (though in colloquial Kenyan Swahili, forms like atakukula are very common). Because the object marker -ku- replaces the infinitive ku-, atakula can mean either "he/it will eat you" (Subject + Tense + Object + Root) or "he/it will eat" (Subject + Tense + Infinitive + Root). These two phrases look and sound completely identical, creating an ambiguity between the object marker and the infinitive! Note that if the verb is actually in the infinitive form, the infinitive ku- is retained (e.g., kukula "to eat you").
• Before Vowels: For the vast majority of vowel-initial verb roots, the object marker remains -ku- (e.g., nakuona "I see you"). However, with a few specific verbs like -ambia (tell), it often contracts to -kw- (e.g., nitakwambia "I will tell you").
• The "Double ku" Scenario: Swahili uses ku for several things. Don't confuse this object marker with the past negative -ku- or the infinitive ku-. When you need both, they stack side-by-side! For example, sikukuona means "I didn't see you" (si-ku-ku-ona = I-past.negative-you-see), and kukuona means "to see you" (ku-ku-ona = infinitive-you-see).