立つ

1. Origins, structure, and basic meaning

• Structure: The spelling is 立つ, read たつ, and it is a godan intransitive verb for being upright on one's feet or rising from a seated position.
• Basic usage: 立つ means to stand in an upright position or to stand up after sitting.

2. Common pitfalls and similar expressions

• A continuing standing posture and the moment of rising
  • The forms are 立って and 立つ. The first forms a continuing state at a station entrance; the second marks standing up after sitting long enough for the legs to tingle.
• A friend at the station entrance and tingling after sitting
  • 駅の入口に友人が立っている。 — My friend is standing at the station entrance.
  • 長く座っていたので、立つと足が少ししびれた。 — After sitting for a long time, my legs tingled slightly when I stood up.