idea

PLAN

A1a suggestion or plan for doing something

• That's a great idea!
• I have an idea – let's have a picnic.

KNOWLEDGE

A2knowledge or understanding of something

• I have no idea where she is.
• Do you have any idea how much this costs?

OPINION

B1an opinion or belief

• He has some strange ideas about education.

PURPOSE

B1the purpose of something

• The idea of the game is to collect as many cards as possible.