I have always read in grammar books that consider is a verb followed by a gerund , but yesterday somebody showed me a book that claims that consider can be followed either by a gerund or and infinitive, I'm confused now.....
As far as I know, the verb "consider" in its active form is only followed by a gerund:
I considered going to university but went to technical college instead.
I am considering eating a second piece of cake!
In the passive or participle form (be + considered), it is followed by an infinitive, but it is often (always?) a "be" verb that is optional:
He is considered [to be] a great teacher
I am considered [to be] a funny person
Hope that helps!