と

1. Origins, structure, and basic meaning

• Structure: Expressions of state or manner take と to modify an action, as in 堂々と and にこにこと.
• Basic usage: In 彼は質問に堂々と答えた。, it describes the manner of answering.

2. Common pitfalls and similar expressions

• Distinct from に with na-adjectives
  • 堂々と答える and 静かに答える both modify how someone answers, but use different connections. Similar adverbial meanings do not require the same particle.
• Forms without と
  • Some words can also appear without と, as in ゆっくりと歩く and ゆっくり歩く. Omission depends on the word rather than a single rule for all manner expressions.