Invariable Numbers from Six

Level 1

In Swahili, the numbers 6 (sita), 7 (saba), 9 (tisa or kenda), and 10 (kumi) are invariable—meaning they never change their form to agree with the noun they are counting. While some of these were borrowed from Arabic, others are native Bantu words.

How It Works

When counting in Swahili, numbers fall into two main groups: those that take agreement prefixes and those that do not.

The Invariable Numbers:
Numbers like 6 (sita), 7 (saba), 9 (tisa or the native kenda), 10 (kumi), 20 (ishirini), and 100 (mia) never change. For example, "six books" is vitabu sita, not sita vitabu.

The Variable Numbers (1–5 and 8):
These numbers require prefixes to match the noun:

  • 1 = -moja (takes singular prefixes)
  • 2 = -wili (takes plural prefixes)
  • 3 = -tatu (takes plural prefixes)
  • 4 = -nne (takes plural prefixes)
  • 5 = -tano (takes plural prefixes)
  • 8 = -nane (takes plural prefixes)

Note on the number 2: When counting abstractly (1, 2, 3...), you say mbili. However, mbili is just the Class 10 form; the actual root used for agreement with other nouns is -wili (e.g., watu wawili for "two people").

The N-Class Illusion: For N-class nouns (Classes 9/10), the agreed forms for these variable numbers (moja, mbili, tatu, nne, tano, nane) look exactly like the abstract counting numbers. This can make them seem invariable, but they are actually taking N-class agreement.

Compound Numbers:
In Standard Swahili, when forming compound numbers (like 12 or 24), the final digit determines the agreement. If it ends in 1–5 or 8, it takes a prefix. Crucially, if the compound number ends in 1 (like 11, 21, 31), the final digit takes a singular prefix even though the noun is plural (e.g., "eleven people" is watu kumi na mmoja, not wamoja). For example, "twelve people" is watu kumi na wawili. However, in everyday colloquial speech, native speakers frequently drop this agreement and just use the abstract counting numbers (e.g., watu kumi na mbili).

The Tens Stay Unchanged:
Watu kumi na wawili means “twelve people”; do not write wakumi. Agreement appears on the variable unit, not kumi. Nyumba kumi na moja means “eleven houses”: moja is the relevant one-form here and does not need an invented nasal prefix. The ordinary model also has magari kumi na moja; the visible agreement differs by noun class and convention.

Examples (4)

  1. Nina vitabu tisa.

    I have nine books.

    Word by Word: I have books nine.

    The number tisa (9) follows the noun vitabu and does not take a prefix.

  2. Watoto sita wanacheza uwanjani.

    Six children are playing in the field.

    Word by Word: Children six are playing in field.

    Sita (6) is invariable and does not take the wa- prefix, even though it modifies watoto.

  3. Watu kumi na wawili wamefika.

    Twelve people have arrived.

    Word by Word: People ten and two have arrived.

    In the compound number 12, kumi is invariable, but the final digit -wili (2) takes the wa- prefix to agree with watu.

  4. Alinunua kalamu saba.

    He bought seven pens.

    Word by Word: He bought pens seven.

    Saba (7) follows the noun and remains unchanged.

Common Mistakes

  • Adding noun-class prefixes to invariable numbers.

    Watu wasita wamefika.
    Watu sita wamefika.

    Learners often assume all numbers take agreement prefixes. However, sita (6) is invariable and never takes a prefix.

  • Placing the number before the noun.

    Nina tisa vitabu.
    Nina vitabu tisa.

    In Swahili, numbers must always come after the noun they modify.

  • Forgetting to inflect the final digit in compound numbers.

    Watu kumi na mbili wamefika.
    Watu kumi na wawili wamefika.

    In Standard Swahili, if a compound number ends in 1–5 or 8, the final digit must take a noun-class prefix to agree with the noun.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

Invariable Numbers from SixLevel 1

Learn This First

To understand cardinal numbers 6 and above, a learner must first be familiar with the general system of noun class agreement in Swahili. This provides the necessary contrast to understand that these specific numbers are 'invariable'—meaning they do not take prefixes. Familiarity with other invariable adjectives and the interrogative for quantity (-ngapi) helps place these numbers within the broader grammatical framework of quantification.

Words in This Pattern

sitasitasabasabatisatisakumikumikumi