La siguiente sintaxis
se usa en comparativos.
AS + Adjectivo + AS.
NOT AS + Adjectivo + AS.

La siguiente sintaxis no
se usa en comparativos.
NOT SO + Adjectivo + AS.
No tan ... que ...
No tan ... como ...
No tanto ... como ...

NOT SO MUCH.... AS A...
No tanto como un...
NOT SO MANY...... AS A...
No tantos como un...

SO MANY
Tantos.
So many people.
Significa tanta gente.
SO MANY...... AS
Tantos como.
AS PEOPLE OR SO PEOPLE.
Se traduciría como Tan gente.

La construccion NOT AS ... AS
es muy usada en el ingles informal
en lugar de NOT SO ... AS.
Es un poco menos
formal que LESS ... THAN.
Ejemplos:
MONT BLANC IS
NOT AS HIGH AS MOUNT EVEREST.
El Mont Blanc no es tan alto
como el monte Everest.

Norway is not as sunny as thailand.
Noruega no es tan soleada como Tailandia.

A bicycle is not as expensive as a car.
una bicigleta no es tan cara como un coche.

Arthur is not as intelligent as Albert.
Arturo no es tan inteligente como Alberto.

En ingles moderno nunca se
usa SO ... AS en sentencias
comparativas, sino AS ... AS
Ejemplos:
Formal:
HE IS LESS RELIABLE THAN HIS BROTHER.
(El es menos fiable que su hermano),
Informal:
HE IS NOT AS RELIABLE AS HIS BROTHER.
Formal:
ARNOLD IS LESS CONFIDENT THAN CHARLES IS.
(Arnold es menos confiado que su hermano).
Informal:
ARNOLD IS NOT AS CONFIDENT AS CHARLES IS.
Formal:
THE RED BICYCLE IS
LESS EXPENSIVE THAN
THE BLUE ONE.
La bicigleta roja es menos cara que la azul
Informal:
THE RED BICYCLE IS
NOT AS EXPENSIVE AS
THE BLUE ONE.

Frases equivalentes:

He is not

so as

tall as

i am. me.

The chair is not

so as

big as

the table (is).

Otros ejemplos:
Norway is not as sunny as thailand.

Arthur is not as intelligent as albert.

A bicycle is not as expensive as a car.

Mont blanc is not as high as mount everest.

You are not so quiet as he is.
(No eres tan tranquilo como es el).

I don't speak so much as she does.
(Yo no hablo tanto como el).

The door is not so high as the window.
(La puerta no es tan alta como la ventana).

Para los adjetivos en que el
comparativo finaliza en ER,
se puede usa NOT AS ... AS
o la forma comparativa de un
adjetivo de significado distinto.

Por ejemplo, la sentencias de
abajo tienen el mismo significado:
HE IS NOT AS OLD AS HIS SISTER.

HE IS YOUNGER THAN HIS SISTER.

THIS CHAIR IS HARDER THAN THAT ONE.

THIS CHAIR IS NOT AS SOFT AS THAT ONE.