Some English phrases

It's not rocket science

• "Everybody knows how to cook boiled eggs, it's not rocket science"
• Ce n'est pas sorcier

To blow one's own trumpet

• To boast
• Se vanter
• "Bob is always reminding us he knows famous people and owns a ferrari"
• He blows his own trumpet

No room to swing a cat

• Very small
• "Your flat in Tokyo is cheap but there is no room to swing a cat"
• Pas de place pour se retourner

The dog's bollocks

• The best of the best
• Nec plus ultra
• (Britain, vulgar slang) Something that is regarded as outstanding.
• "Your Christmas meal was the dog's bollock"

A catch 22

• A no-win dilemna of contracdictory rules
• Perdant gagnant
• L'un dans l'autre ... je m'y retrouve
• catch 22
• A situation in which a desired outcome or solution is impossible to attain because of a set of inherently illogical rules or conditions.
• A contradictory or self-defeating course of action.
• Urbandictionnary.com

Choc-a-block

• Very crowded
• "The metro was chock-a-block this morning. There were too many people."

Other fish to fry

• To be busy and not have time to do something else
• D'autres chats à fouetter
• "I don't have time to chat and drink coffee, I've got other fish to fry"

to spend a penny

• To go to the restroom:
• I need to spend a penny
• j'ai besoin d'aller au p'tit coin

Out of the blue

• Sudden and unexpected
• "One day, out of the blue, the cat came back home."