台 (dai): Counting Machines and Vehicles
Quick Answer: 台 counts machines, vehicles, and large equipment: cars, bicycles, computers, TVs, washing machines, pianos, etc. No sound changes — always だい: いちだい, にだい, さんだい.
Cars, computers, TVs, and mechanical things
Category: Counters
The Rule
台 counts machines, vehicles, and large equipment: cars, bicycles, computers, TVs, washing machines, pianos, etc. No sound changes — always だい: いちだい, にだい, さんだい. The concept is 'things that sit on a platform or have a mechanical function.'
Why This Matters
台 literally means 'platform/stand,' and the counter extends to anything mechanical or that sits on a base. English speakers sometimes confuse which objects use 台 vs つ. The rule of thumb: if it has an engine, motor, screen, or keyboard, use 台. Traditional furniture and simple objects use other counters.
Examples
• 車を二台持っています。 — "I own two cars." [にだい = 2 vehicles] • 新しいパソコンを一台買いました。 — "I bought one new computer." [いちだい = 1 machine] • エレベーターが三台あります。 — "There are three elevators." [さんだい = 3 (mechanical units)] • 洗濯機と乾燥機、合わせて何台ありますか？ — "How many washers and dryers are there in total?" [何台 = なんだい — appliances use 台]
Common Mistakes
❌ 自転車を三つ ✅ 自転車を三台 → Bicycles are vehicles — use 台, not つ. Even though bikes are simple, they're vehicles with wheels ❌ 机を一台 ✅ 机を一つ / 一脚 → Desks are furniture, not machines. Use つ (general) or 脚 (きゃく, for furniture with legs)
Quick Tip
Quick test: Does it use electricity, have an engine, or have wheels? → 台. This covers cars, bikes, TVs, phones, computers, washers, air conditioners, and pianos (mechanical keys).
Quick test: Does it use electricity, have an engine, or have wheels? → 台. This covers cars, bikes, TVs, phones, computers, washers, air conditioners, and pianos (mechanical keys).
Examples
Common Mistakes
Incorrect: 自転車を三つ → Correct: 自転車を三台. Bicycles are vehicles — use 台, not つ. Even though bikes are simple, they're vehicles with wheels
Incorrect: 机を一台 → Correct: 机を一つ / 一脚. Desks are furniture, not machines. Use つ (general) or 脚 (きゃく, for furniture with legs)
Quiz
Which item would NOT use 台?