Great idea.

Meaning: This means a thought or suggestion that is considerably above average. It's like saying, The suggestion that is very good.

Choice of Words: Great is an adjective that means of an extent, amount, or intensity considerably above the normal or average. Idea is a noun that refers to a thought or suggestion as to a possible course of action. In this context, "Great idea" refers to a thought or suggestion that is considerably above average.

Alternative Expressions

Your idea is great.

Meaning: This is a way to tell someone that you really like their thought or plan. It's like saying, "I think your idea is really good" or "Your plan is excellent!"

Choice of Words: The word "your" shows that the idea belongs to someone specific. "Idea" is a noun that refers to a thought or plan. "Great" means very good or excellent. When you put them together, "your idea is great" means that the person's thought or plan is very good or excellent.

Related Expressions