something not sure about..

[amy_bp]

I have a simple question...

when you use "should" in a sentence with the 3rd. person how do you write the verb?

I think that is in this way: " He/She Should KNOW " without the s in the verb, but someone told me that when you use it in question way that´s the correct way.. but if it´s an afirmation you should write it like " He/She should KNOWS " with the third termination in the verb.

So I am confused.

thanks for your help

[Tdol]

She should know

After a modal verb, we don't add the -s. I'm afraid the person who told you that is wrong.