Here is an English grammar lesson and exercises about the used + infinitive structure.In this lesson, I explain the meaning and use of the used to + infinitive structure. This is a very common structure in the English language.We use it to describe a regular habit or action in the past that we no longer have or do in the present. Example: "Mark used to work in an office but now he works in a restaurant."It also describes a state we had previously in the past, example: "He used to like cheese but now he hates it."I explain in detail the affirmative form, question forms and negative form (including the contracted form) of the used + infinitive structure.