"He rightly thinks that an international language must be an easy language."
Translation:Li prave pensas, ke internacia lingvo devas esti facila lingvo.
Shouldn't this be "kredas", as in believes, rather than "thinks" as is common in english?
In some romance languages (such as Italian) we also use "to think" in that way.
In english thinks would be based on facts, believes would be just an opinion. In this case the idea is much more than mere opinion or belief, it is a practical fact.