当てる

1. Origins, structure, and basic meaning

• Structure: 当てる (あてる) is a transitive verb with several senses, including to guess correctly and to apply or press something against another object.
• Basic usage: Context distinguishes identifying an answer from bringing one object into contact with another.
  • 箱の中に何があるか音だけで当てた。 — I guessed what was in the box from the sound alone.
  • 寒かったので両手を湯のみの側面に当てた。 — It was cold, so I pressed both hands against the side of the teacup.

2. Common pitfalls and similar expressions

• Object determines the sense
  • With an answer or hidden content, it means to guess; with hands, light, or another object, it means to apply or place against. Check the object even when the form is the same 当てた.