Subject Agreement

Understanding subject agreement is the most important step to become confident with Swahili sentences. Here are the big-picture rules:

• It is mandatory for most tenses: Even if you say the subject's name explicitly (like 'the child'), the verb still needs its subject marker. You cannot drop it in standard tenses. Exceptions include commands, infinitives, and the Habitual hu- tense.
• It acts as a pronoun: Because the marker tells us exactly who is acting, Swahili often drops the standalone pronoun (I, you, he, she). This is known as Omitted Subject Pronouns. The basic conversational markers are ni- (I), u- (you), a- (he/she), tu- (we), m- (you all), and wa- (they). For example, anasoma means 'he/she is reading' all by itself. Note that when a sentence is negative, a negative prefix is usually added. For most subjects, the prefix ha- is added before the subject marker (like ha- + tu- = hatu- for 'we', ham- for 'you all', and hawa- for 'they'), though ha- + a- merges to just ha-, ha- + u- merges to hu- for 'you', and for 'I', si- completely replaces ni-.
• Animals are treated like humans: Swahili grammar respects animacy. Even if an animal belongs to an 'inanimate' noun class, in Standard Swahili it almost always takes human subject markers. Singular animals take the Class 1 Subject a-, while plural animals take the Class 2 Subject wa- (e.g., mbwa wamelala - the dogs are sleeping). This is called Animate Concord.
• It changes with number and noun class: A common myth is that you just copy the first letters of the noun onto the verb. While this happens sometimes (kitabu kilianguka), it is often different. Furthermore, inanimate objects use specific subject markers (like i-, zi-, li-, or ya-) depending on their assigned Noun Classes, not just whether they are singular or plural (e.g., mti ulianguka becomes miti ilianguka).
• Locations have their own markers: When a place or location is the subject of a sentence, the verb takes a locative subject marker (pa-, ku-, or mu-). For example, pahali hapa panapendeza (this place is pleasing). This is known as Locative Subject Agreement.

To see exactly where this fits into the verb, check out the Verb Slot Order. Keep in mind that negating a verb is more complex than just adding a prefix; it often involves dropping or changing the tense marker and changing the final vowel. For example, in the present tense, the affirmative tense marker -na- drops entirely and the final vowel changes from -a to -i (e.g., 'I am not reading' is sisomi, not sinasoma).