Maria Iglesia Ramos (asker) May 11, 2015:

@Maris You answered my question accurately. Many thanks Maria. Have a nice day.

Maria Ortiz Takacs May 11, 2015:

About the -ing form A small note on grammar that can be helpful: the -ing form in your sentence is not a gerund but a present participle while the -ed forms are past participles. You need to take all of them with the "are" that appears first in the sentence, so basically, it reads "once you are hooked, once you are committed, once you are cohabiting, etc." Hope it helps!