Trouble Spots
to THINK OF / ABOUT: penser à, penser de
penser à: the brain is engaged in the thought process; to have ideas
--À quoi penses-tu?
-- Je suis triste. Je pense à mes parents.
penser de: to have an opinion about something
--Qu'est-ce que tu penses de ma jupe?
[What is your opinion of...]
--Quelle horreur! Elle est attroce! Berk!