Grammar rule

[elaine1920]

I run across "as...as", "so...as" and "so...as to be", "enough that"...these 4 idioms but always confused by the rule.

Can anyone please clearify the usage here?

What I know so far is, as...as (e.g. as much as) can be used in positive and negative sentence, while so...as can only be used in negative.

Then when it comes "so..as to be", I saw the usage in GMAT Prep, but wasn't sure if we can use in positive and negative sentences?

Also, for "enough that", is this a proper usage? it sounds right to my ear. Also, is "enough to be" a right usage? ( this one sounds wrong to me, but I wasn't 100% sure)


thanks in advance!

[RonPurewal]

What I know so far is, as...as (e.g. as much as) can be used in positive and negative sentence, while so...as can only be used in negative.

hmm.

where'd you get this information?

could you provide an example of "so ... as", which, you say, can only be used in contexts with a negative connotation?

Then when it comes "so..as to be", I saw the usage in GMAT Prep, but wasn't sure if we can use in positive and negative sentences?

there is no inherent connotation attached to this construction; it just suggests that the extent of something is extreme.

tall enough to reach over this wall doesn't suggest anything unusual about the height of the wall or of the person reaching over it.
so tall as to reach over this wall suggests that the person reaching over the wall is of exceptional height.

Also, for "enough that", is this a proper usage?

nope.

Also, is "enough to be" a right usage?

yes.