one

1. Origins, structure, and basic meaning

• Structure: 一 uses one horizontal stroke to represent ‘one.’
• Basic usage: The following word determines what is counted or how the expression functions as a whole.
  • 一つ counts one physical object or one item such as a question.
  • 一人 means one person, while 一人で describes doing something alone.

2. Common pitfalls and similar expressions

• Readings
  • The representative readings いち and ひと cannot be attached unchanged to every word containing 一.
  • 一つ is read ひとつ, and 一人 is read ひとり.
  • 一日 is read ついたち for the first day of a month and いちにち for a period of one day.
• Order and degree
  • 一番 can express being first in an order or the highest degree, as in liking something best.
• Alone and together
  • 一人で describes acting alone, while 一緒に describes acting with someone.
  • Translating 一緒 character by character as ‘one’ misses the meaning of the complete word.