“To have/get butterflies in (one’s) stomach”. – English idiom

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Example sentences from the web:

  • Her mouth was dry, there were butterflies in her stomach, and her knees were shaking so much it was hard to walk on stage.
  • The first day in front of a class, new teachers always have butterflies in their stomachs.
  • Before I went on stage, I had butterflies in my stomach.

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