EN: to be used to + V-ing / used to + infinitive – present & past habits

“To be used to” is a verbal phrase that cannot be broken up. It can only be used with the verb “to be”. “Used to” by itself is useless when meaning “accustomed to”; it must be accompanied by “to be.” Therefore, one cannot write something like: “I used to going there.” You need to say “I am used to going there.” When meaning “formerly” there is NO “to”; it is just the verb “use” in the past tense. The formula requires it to have “to + verb” after it to be meaningful. Since “use” is the verb, the “to be” part disappears and one is left with “I used + to + verb” which has the sense of “formerly” as opposed to “accustomed.” Great question. I remember learning this growing up, and it was not easy at all. A la prochaine !

Interesting to note: to look forward to is another verb “phrase” that changes meaning when you remove the final preposition. To look foward is different than to look forward to. Since you already have “to” at the end of the latter verb phrase, you cannot attach an infinitive to it because once again you would end up with the “to to” structure. Thus, one must employ a gerund: I am looking forward to hearing from you, and not I am looking forward to to hear from you.

Since it follows the copula “to be”, used is a “predicate adjective” (albeit derived from the verb to use). A predicate adjective is therefore part of the verb phrase. It is all or nothing: “to be used to” can only exist in this form.