-tatu

Three with -tatu

Level 1

In Swahili, the word for "three" is the root -tatu. Because it is a native Bantu number, it must take a prefix that matches the plural noun it describes.

How It Works

While most plural classes add a visible prefix to -tatu (like mitatu for trees or matatu for cars), Class 10 (the plural N-class) is a special case. Because the root starts with the voiceless consonant "t", the N- prefix drops completely. This means you just say tatu (e.g., nyumba tatu for "three houses"), never ntatu or zitatu. This rule also applies to -tano (five). The prefix also drops for -nne (four) and -nane (eight), but because they start with a nasal consonant ("n"). Meanwhile, -wili (two) becomes mbili. Note that Class 10 is also the plural for Class 11 (U-class) nouns, so you will say kurasa tatu (three pages). The question word -ngapi (how many?) behaves exactly like these numbers, taking the same prefixes and following the same N-class dropping rule (e.g., nyumba ngapi?).

Crucially, because of the Swahili Animacy Rule, animate nouns (people and animals) always take Class 1/2 agreement regardless of their noun class. So for three dogs, you must say mbwa watatu, never mbwa tatu.

This agreement rule also applies to the final digit in compound numbers, such as vitabu kumi na vitatu (thirteen books) or mbwa kumi na watatu (thirteen dogs). Remember that only Bantu number adjectives (1-5 and 8) take these prefixes. Arabic-derived numbers like sita (six), saba (seven), and tisa (nine) never change. The word kumi (ten) is a native Bantu word, but it does not take prefixes because it is grammatically a noun (Class 5), not an adjective. Also, don't confuse the counting number "three" with the ordinal number "third", which uses the of-association word. In ordinal constructions, the number root loses its agreement prefix entirely and remains invariable (e.g., kitabu cha tatu, NEVER kitabu cha vitatu), while the of-association word changes based on the noun class.

Number Families:
Class 10 is the plural partner of many Class 9 nouns: nyumba tatu (three houses). Ordinal first and second use separate words, ya kwanza and ya pili with Class 9 agreement, rather than deriving them from moja and mbili. In careful agreement, vitabu kumi na vitatu means thirteen books; reduced vitabu kumi na tatu is also heard in conversation.

Examples (6)

  1. Watu watatu walifika jana.

    Three people arrived yesterday.

    Word by Word: People three arrived yesterday.

    Class 2 (people) uses the prefix wa-.

  2. Nina vitabu vitatu.

    I have three books.

    Word by Word: I have books three.

    Class 8 (KI-VI plural) uses the prefix vi-.

  3. Alinunua nyumba tatu.

    He bought three houses.

    Word by Word: He bought houses three.

    Class 10 (N-class plural) takes a zero-prefix before 't', leaving the bare stem tatu.

  4. Tuna magari matatu.

    We have three cars.

    Word by Word: We have cars three.

    Class 6 (JI-MA plural) uses the prefix ma-.

  5. Miti mitatu ilianguka.

    Three trees fell.

    Word by Word: Trees three fell.

    Class 4 (M-MI plural) uses the prefix mi-.

  6. Alisoma vitabu kumi na vitatu.

    She read thirteen books.

    Word by Word: She read books ten and three.

    In compound numbers, the final digit takes the agreement prefix, clearly seen here with the vi- prefix.

Common Mistakes

  • Forgetting to add the agreement prefix and treating it like an English number.

    Watu tatu walifika.
    Watu watatu walifika.

    Because -tatu is a Bantu root, it must take the adjectival prefix of the noun it modifies (like wa- for people).

  • Using the subject prefix zi- for N-class nouns instead of the correct adjectival form.

    Nina nyumba zitatu.
    Nina nyumba tatu.

    The adjectival prefix for Class 10 is N-, which drops completely before the letter 't'. The prefix zi- is strictly used for verbs and pronouns, not adjectives.

How It Connects

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-tatuLevel 1Three with -tatu

Learn This First

The number -tatu is a variable numeral in Swahili, meaning it requires a prefix that matches the noun class of the object being counted. To use it correctly, you must understand the noun class system and the general rules for noun class agreement.

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Words in This Pattern

tatu