This means something that's done and can't be undone.
Least said, soonest forgotten.
Don't cry over spilt milk.
Sometimes it's best to forget past hurts or mistakes and just move on.
keep it under the hat
She was feeling a bit under the weather, so she didn't go to the movies.
It is not an idiom - it means exactly what it says. Whatever the subject of the sentence is sitting under the sun in the heat.
Peculiar to or characteristic of a given language.Characterized by proficient use of idiomatic expressions: a foreigner who speaks idiomatic English.Resembling or having the nature of an idiom.Using many idioms.Peculiar to or characteristic of the style or manner of a particular group or people.5. a common expression whose meaning cannot be guessed from individual words eg 'I'm feeling under the weather
Your mother tongue is the language that you learned as a child. Another term would be your milk language. This is the language that you understand the best, and with which you are most familiar. It is also the accent that you will speak when you are under stress or with your family.
You wouldn't see that used as an idiom - perhaps you heard "drink someone under the table," which means to be able to drink enough alcohol that the other person is drunk and you are still standing. If you just hear someone say "under the table," they mean it literally.
When people develop some kind of theory, sometimes they need to stop and see how it compares to the real world, before they invest too much intellectual effort in something that might not stand up under such examination, which idiomatically can be called a reality check.
Under the Bridges of Paris was created in 1931.
Yes. Under is a preposition and bridges is the object of under; therefore under bridges is a prepositional phrase.
No, nuns generally live in convents, not under bridges.
"Under field conditions" is more idiomatic.
"Just under the wire", an expression meaning you barely made it.