Qual é a diferença entre eager to do e aspire to do e be keen to do ?Podes indicar apenas respostas exemplo.

Let's start with "aspire."
Aspire to do: to direct hopes or ambitions towards achieving something
In other words, the ~ used in the phrase "aspire to do~" is generally something hard to do or far away from one's reach. It is generally something that the speaker has to direct a lot of time and energy to do.

Examples:
I aspire to be a professional soccer player.
Unlike who my actual father is, I aspire to be a good father to my future children.
She wants to be an idol that other girls will aspire to be like.

Eager to do ~: wanting to do or have something very much
This phrase isn't as ambitious as "aspire to do." It's just another way of saying somebody wants to do something or have something. This "something" is generally not as far away as the "something" in "aspire to do."

Examples: Eager to start playing the new game, he blazed through his homework and ended up making a lot of mistakes.
He was a bit too eager to please, and he ended up misrepresenting his work experience in front of the interviewers.
Ah, Mr. Paddington! We've been waiting for you. Head on in; the boss is eager to meet you.

Be keen to do: having or showing eagerness or enthusiasm
As you can see, "be keen to do" is more or less the same as "be eager to do". You can swap "be keen to do" with "be eager to do" for the above three sentences and their meanings would be the same. It is a little bit more difficult to do for "aspire."