Was that JP in the ninja suit?

Moving right along..

What are the specific names for the various types of underwear?

Boxers, boy shorts, tidy whities, thongs (tangas), speedo style, etc, etc.

me olvido - I forget

te olvidas - you forget

olvídalo, no me voy - forget it, I'm not going

A quick question:  in the vocabulary, you use "ahi" but I've seen the word also as "alli".  Is this correct?  Can you use both/either?  Help me, please!

In practices there is a lot of overlap between ahi and allí.  But for and explanation of their differences try

http://spanish.about.com/od/adverbs/a/here_there.htm

You can also see examples of their uses on wordreference.com

http://www.wordreference.com/es/en/translation.asp?spen=alli

http://www.wordreference.com/es/en/translation.asp?spen=ahi

:-)

They mean almost the same thing, something like "Let's not talk about it anymore."

Usually, if I say "Forget it," I'm the one who brought up the subject. If I say "Drop it," usually you are the one who brought up the subject.

Is that what you were asking?