Bueno y malo

[Caballero]

Is it true that you can use "bueno" and "malo" instead of "sí" and "no"?

[aleCcowaN]

bueno == OK

In those cases when yes, yeah, yup or OK are indistinctly right, you can say "Bueno" in Spanish. It's more an expression of agreement than an expression of assertion.

You can't say "malo" when you mean "no" -unless perhaps in case you are a linesman-.

[CrOtALiTo]

Well in my own experience, I can tell you that they are a meaning very similar between them.

For example.

Si casate
Bueno casate

In both cases they are affirming you something and the word can authorizes the command gave for you.

Yes or good.

No te cases
Malo te cases

In these last phrase they are a little different in the translation.

I consider they are for an specific uses solely yes or not and bad or not.

You can use them correctly each one them as bad and not and good and yes each word has the meaning well defined.

Sincerely yours.

[AngelicaDeAlquezar]

"Malo te cases" is a fragmentary sentence that makes no sense.

A complete sentence would be "Es malo que te cases" (it's bad that you get married).

Alec has given the right answers.