Idiom: Think of... (active and passive)

[qianruS779]

Hi instructor,

I would like to ask you to confirm whether the following idioms are correct in GMAT:

active -- think of X as Y
passive -- X is/are thought to be Y
passive -- X is/are thought as Y

Thank you very much in advance

Best, Song

[RonPurewal]

the first two of those are structures that exist. the third isn't, because the "of" is missing.

to understand how that construction would be built, make an analogy.

analogy:
People commonly use concrete as a building material.
--> Concrete is commonly used as a building material.

make sense?

once you have that, you'll see how you would have to make the construction you want here:
People commonly think of concrete as a building material.
--> Concrete is commonly thought of as a building material.

so, you'd have to have "thought of as".

this is pretty awkward in writing, so, it's unlikely to appear in a correct GMAT sentence. not impossible, but unlikely.

[qianruS779]

Nice explanation! Thank you!!

Best, Song

[RonPurewal]

you're welcome.