The Final Vowel

Because dictionaries list native Bantu verbs with the -a attached (like soma), learners often mistakenly believe the -a is an inseparable part of the base word. Linguistically, the core root is just the consonants and internal vowels (e.g., -som-), and the final vowel is a removable grammatical suffix.

For native Bantu verbs ending in -a, the end of a Swahili verb carries just as much grammatical weight as the prefixes at the beginning. You must read the whole word to know its tense and mood!

The Three Main Endings:

• -a (Statements, Infinitives & Singular Commands): Used for regular facts, dictionary forms, and basic singular commands (e.g., Soma! "Read!"). See Infinitive ku- and Singular Imperative.
• -i (Present Negative): Used when saying someone is not doing something right now, or as a general habit. See Present Negative -i.
• -e (Subjunctive & Negative Commands): Used for polite requests, suggestions ("should/let's"), obligations, and negative commands (e.g., usisome "don't read"). See Subjunctive -e and Singular Negative Command.

Plural Commands: When giving a command to multiple people using regular verbs ending in -a, you change the final vowel to the subjunctive -e and add the plural enclitic -ni (e.g., soma becomes someni). See Plural Imperative -eni.

Commands with Object Prefixes: When you add an object prefix to a command, the final vowel must change from -a to -e (e.g., saidia becomes nisaidie "help me").

Note on Short Verbs: Monosyllabic verbs (like kula or kunywa) drop their ku- prefix when taking the -i or -e endings (e.g., sili "I do not eat", where the subject prefix ni- becomes the negative si-, and nile "let me eat"). However, they retain the ku- prefix for the singular imperative because it uses the standard -a ending (e.g., Kula!, Kunywa!), and when forming the plural imperative with -ni (e.g., kuleni). Note that kuja and kwenda are highly irregular (njoo/njooni and nenda/nendeni). See Ku- Retention in Short Verbs.

The Exception: Borrowed Verbs
Many common verbs come from Arabic (like kujibu "to answer" or kusamehe "to forgive"). If they naturally end in -e, -i, or -u, they are exempt from these rules and their final vowels do not change in the subjunctive or present negative. For the plural imperative, they simply add -ni (e.g., jibuni). However, if a borrowed verb ends in -a (like kusaidia) or takes a suffix that makes it end in -a (like the passive kujibiwa), it follows the standard vowel-change rules. See Borrowed Verb Endings to become comfortable with these exceptions.