"I'm not as tall" = "I'm not as tall as something"?
"I'm not as tall" = "I'm not as tall as he"
"It's not as big" = "It's not as big as the other one"
"She's as smart" = "She's as smart as all the other genius"
... and such..
Are they correct?

I've seen many times that a sentence ends with only one 'as' used just like things above. I've always considered that the former is the shorter version of the latter, but I didn't see any reference saying like that, so I wanted to make sure if I'm correct.

Question

"I'm not as tall" = "I'm not as tall as something"?
"I'm not as tall" = "I'm not as tall as he"
"It's not as big" = "It's not as big as the other one"
"She's as smart" = "She's as smart as all the other genius"
... and such..
Are they correct?

I've seen many times that a sentence ends with only one 'as' used just like things above. I've always considered that the former is the shorter version of the latter, but I didn't see any reference saying like that, so I wanted to make sure if I'm correct.

Answer

Those of the type: "I'm not as tall." Only mean that the object they are compared to is in the previous contex thus no need to repeat it. All of them are correct.

Answer

The number of "as" used will depend on when are you saying it.

If it is the first time you are making reference to someone/something, you have to use "as ~ as someone/something".

Example:

A: Why are you looking so down?

B: I can't help but feel that I am not as smart as my siblings lately.

However, if you were already in the middle of the conversation with someone and the reference point/noun as already been mentioned, then you can simply use one "as".

Example:

Coach: You may be new to the team but your skills is on par with many of your seniors.

Student: Thanks for the compliment but I am not as good (You may also choose to say "I am not as good as them", if you wish to).

Answer

@eleonoradelidou Thank you!!! :D

Answer

correct is the second but when you speak you can eat some words