Could you please shed some light on this?
a) I am used to studying 12 hours a day. (gerund)
b) I used to study 12 hours a day. (infinitive)
My doubt: Do they ALWAYS work like stated above? I mean, is there any possibility for sentence b) to be written like this?
I am used to < infinitive>. = I am accustumed to < infinitive>
So, it is safe to say that after 'to be used to' there will ALWAYS be a gerund, once it makes reference to customary actions.