Translation guide
The number nine in Japanese is 九 (きゅう/く). However, counting objects, people, and other things requires specific counters, and the pronunciation changes depending on the counter.
nine (number)
Use きゅう for most contexts. く is also used but can be avoided due to association with suffering.
Expressing the number nine in isolation, such as in math, phone numbers, or counting without a specific counter.
The most common on'yomi reading for the number nine. Used in counting, phone numbers, and many compounds.
Nine is my lucky number.
An alternative on'yomi reading, often used in some fixed phrases and when counting from one to ten. Can be avoided in some contexts because く sounds like 苦 (suffering).
One, two, three, four, five, six, seven, eight, nine, ten.
Counting generic objects or when the specific counter is unknown. Uses the counter つ.
The native Japanese counting word for nine items. Used for general objects, often when a specific counter is not required.
Please give me nine apples.
Specifying nine people.
The standard counter for people. Note the reading is きゅうにん, not くにん.
Nine people are coming.
Counting small to medium-sized animals, fish, or insects.
Counter for small animals. The reading of 匹 changes to ひき due to rendaku.
There are nine cats.
Counting flat, thin objects.
Counter for flat objects like sheets of paper, tickets, or dishes.
I used nine sheets of paper.
Counting long, thin objects.
Counter for long objects. The reading of 本 changes to ほん after きゅう.
I bought nine pens.
Counting small, roughly spherical objects.
Generic counter for small items, often used for round objects. 個 is very versatile.
I boiled nine eggs.
Stating someone's age as nine.
Standard counter for age. Also written as 九才.
My daughter is nine years old.
English 'nine' cannot simply be translated as 九 when counting objects. You must use the appropriate counter word. Saying '九りんご' is incorrect; use 'りんご九つ' or 'りんご九個'.
The reading of the counter often changes depending on the number. For example, 九匹 is きゅうひき, not きゅうびき or くひき. Learn the common combinations.