"Encontrei uma caneta vermelha em cima do livro" would be "I found a red pen ON the book" or "I found a red pen ON TOP OF the book" ? What about " I've found a red pen ......." is it possible??
Thanks in advance.
Um guia para quem estuda Inglês Online
on top of something:
 [fig] up-to-date on something; knowing about the current state of something.
 [fig] in addition to something.
 [fig] victorious over something; famous or notorious for something.
Retrieved from: < http://idioms.thefreedictionary.com/on+top+of >
to be on top of something = to be able to control a situation or deal with it.
Retrieved from: < http://dictionary.cambridge.org/diction ... top-of-sth >