Adjectives and adverbs

[Gabrielle Sigaki]

Hey guys, in which situations is it okay to use some adjectives as adverbs?
For example:
He was real insecure.
She made the test quick.

I saw some people using it like that and a lot of sites say that it's okay to do that in an informal situation or when it is the style of the author(in a book), but still, I don't know for sure.

[MrsCatInTheHat]

Neither one of those sentences work well for me. The first should be, "He was really insecure." The second is unclear in it's meaning. Does it mean the teacher created a test to be taken quickly? Or that a student took it quickly? Or what?

[Gabrielle Sigaki]

I think that kind of use makes the sentences confusing too, but still, there are a lot of books that use adjectives as adverbs, so I was unsure if it had something to do with the writer's style.

[Gift Sidira Munthali]

In the first statement I think should be "He was really insecure" but the second statement I don't know how made the test quick, is it a teacher or a student?

[emidio125]

In the first example.

[A Y reviews]

Wow i should have visited here much earlier. Thanks guys