つ

The counter つ is a 'catch-all' counter for inanimate objects and abstract concepts. If you aren't sure which specific counter to use for an inanimate object (like 枚 for flat things or 本 for long things), つ is usually a safe and natural choice. Note that while it cannot be used to count the number of living things (like people or animals), it can be used to state their age.

1. The Number Series:
You must use the native Japanese numbers with this counter. A common mistake is trying to attach つ to Sino-Japanese numbers (like いちつ or につ)—this is incorrect! Also, notice the double consonant (small っ) pattern for 3, 4, 6, and 8（みっつ、よっつ、むっつ、やっつ）. Note that the numbers 1 through 9 all end in つ, but 10 is simply とお. To express 'zero' items, you can use ゼロ or 零（れい）without the つ counter, but the most natural way is to use 一つも（ひとつも）followed by a negative verb (e.g., 一つもありません).

• 1: 一つ（ひとつ）
• 2: 二つ（ふたつ）
• 3: 三つ（みっつ）
• 4: 四つ（よっつ）
• 5: 五つ（いつつ）
• 6: 六つ（むっつ）
• 7: 七つ（ななつ）
• 8: 八つ（やっつ）
• 9: 九つ（ここのつ）
• 10: 十（とお）

2. Asking 'How Many':
To ask 'how many' using this system, use the question word いくつ. For example: 「りんごをいくつ買いましたか？」（How many apples did you buy?）

3. Word Order:
The most natural way to use counters is placing them after the particle that follows the noun: [Noun] + [Particle] + [Counter].
Example: りんごを二つ（ふたつ）食べました。（I ate two apples.）

Alternatively, you can place the counter before the noun using the particle の: [Counter] + の + [Noun].
Example: 二つ（ふたつ）のりんごを食べました。（I ate two apples.）

4. Ordering Food and Drinks:
One of the most practical and common uses of つ is ordering items at a restaurant or cafe. When you want to order portions or items, you can simply use the item name followed by the つ counter. For example: 「コーヒーを二つお願いします」（Two coffees, please.）

5. Usage Limits:
This system only goes up to 10. For physical objects 11 and above, Japanese speakers switch to Sino-Japanese numbers with the 個（こ）system (e.g., 11 is 十一個 / じゅういっこ) or use other specific counters. For abstract concepts 11 and above, it is common to drop the counter entirely and just use the bare number (e.g., 理由が十一あります / りゆうがじゅういちあります or 十一の理由 / じゅういちのりゆう), though using 個 is also acceptable.

6. Abstract Concepts:
While many counters only work for physical objects, つ is perfect for abstract items like 'one wish'（願いが一つ / ねがいがひとつ）or 'two mistakes'（間違いが二つ / まちがいがふたつ）. Crucially, while つ and 個 are largely interchangeable for physical objects from 1 to 10, 個 sounds unnatural for abstract concepts, making つ the grammatically standard choice.

7. Stating and Asking Age:
The つ system is also the traditional way to state age for children from 1 to 9 years old (e.g., 三つ / みっつ for a 3-year-old). For ages 11 and up, you must use the specific age counter 歳（さい）. A famous exception and remnant of this native counting system is 二十歳（はたち）for a 20-year-old. Additionally, いくつ (or the polite form おいくつ) is the standard way to ask someone's age: 「おいくつですか？」（How old are you?）