king/a king? president/a president?

[jjoonam]

There was a song from the animation movie "Lion King" -
"I just can't wait to be king".

In this sentence I thought it should be like,
"I just can't wait to be a king".

Why was "a" omitted?

Similar sentence is like,
"I am president of the US".

Shouldn't this also be
"I am the president of the US", or "I am a president of the US" ?

Please explain.

[Leandro-Z]

There was a song from the animation movie "Lion King" -
"I just can't wait to be king".

In this sentence I thought it should be like,
"I just can't wait to be a king".

Why was "a" omitted?

Similar sentence is like,
"I am president of the US".

Shouldn't this also be
"I am the president of the US", or "I am a president of the US" ?

Please explain.

The correct way would be "I just can`t wait to be a king". It is wrong if you don`t put "a" because "king" is a noun. However, if you see it from the point that nouns in certain situations can become adjectives it is okay. By the way, the correct of both "I am the president of the USA" and "I am a president of the USA" is the first one. While THE is a determiner, A is a quantifier. In a country, only one person can be president, so you can`t say I am one of the 3 presidents.

[saga me holla]

There was a song from the animation movie "Lion King" -
"I just can't wait to be king".

In this sentence I thought it should be like,
"I just can't wait to be a king".

Why was "a" omitted?

Similar sentence is like,
"I am president of the US".

Shouldn't this also be
"I am the president of the US", or "I am a president of the US" ?

Please explain.

If the sentence was, "I just can't wait to be a king," we don't know what kind of king he wants to be. Maybe it means the King of England, or the King of Mordor, or the King of Rock and Roll. It could be anything.

The "a" was omitted in the song because in Simba's case, we know which king he wants to be. He wants to take the position of his father. Thus, "I just can't wait to be King" is more natural here.

"I just can't wait to be the King" is also acceptable. The difference between "I just can't wait to be King/be the King" is so subtle that most native speakers wouldn't make a distinction. If we must do so, "to be King" carries a connotation of living in a certain state of being, while "to be the King" carries a connotation of a person filling a role.

It's the same for President. "I am President" and "I am the President" carry very similar meanings -- "I fulfill the role of president," while "I am a president" would be strange in most situations.