-me-

The -me- perfect tense is one of the most common and important tenses in Swahili. It has two main uses that you should become comfortable with:

• Completed actions with current relevance: Unlike the past -li- marker which places an event in the past without itself foregrounding its present result, -me- means the result is still true right now. Amefika means "He has arrived" (and he is still here).
• Current states: For verbs that describe a change of state, -me- translates to the English simple present tense. For example, kuchoka means "to become tired." So, nimechoka literally means "I have become tired," but we translate it naturally as "I am tired." This is also extremely common with inanimate objects across all noun classes to describe their current state (e.g., Gari limeharibika - "The car is broken").

When using short, monosyllabic verbs (like -la for eat, or -nywa for drink), you must keep the infinitive ku- marker. For example, you say nimekula (I have eaten), not nimela. However, if you include an object infix, the ku- is dropped because the object infix takes over the stress (e.g., nimekila for "I have eaten it", not nimekukila).

To emphasize that an action is already complete, you can use the -sha- already marker to form -mesha- (or -mekwisha-). For example, nimeshafika means "I have already arrived."

Note that -me- is only used in affirmative (positive) sentences. It does not change the final vowel of the verb. To form the negative, you must use the perfect negative -ja- marker instead (Negative Subject Prefix + -ja- + Verb Stem, such as si-, hu-, ha-, hatu-, ham-, hawa- + -ja- + verb). This negative form is very frequently paired with the word bado (still / not yet). For example, amefika (he has arrived) becomes bado hajafika (he has not yet arrived). Crucially, this also applies to stative verbs: to say "I am not tired," you must use the -ja- tense (sijachoka). If you use the standard present negative (sichoki), it means "I don't get tired" as a general habit. Interestingly, the strict rule for keeping ku- with short verbs is flexible in the negative; both hajakula and hajala (he has not eaten) are acceptable.

Another important grammatical restriction is that the -me- tense cannot take a relative infix (e.g., *ame-ye-fika is incorrect). To form a relative clause with the perfect tense, you must use the independent amba- with perfect relative pronoun (e.g., ambaye amefika) or default to the past tense relative.

Not Yet versus Already:
Nimeshasoma means “I have already read.” Its ordinary not-yet counterpart is Bado sijasoma (I have not read yet), not sijameshasoma. The negative -ja- construction does not simply keep -mesha- and add another negative prefix.