Infinitive of purpose   using “to + infinitive”

Examples:

•    I will lock the door to prevent theft.

•    The students studied very hard to pass the exams.

•    The teacher got permission from the principal to      take the children to the museum.

•    Marry listened to him carefully to understand him.

•    She is going to go to England to learn English.

•    To get an outside line, you have to dial 9 first.

•    My friend went home to do her homework.

•    The doctor completed the preparations to operate the patient.

•    The parent is calling the teacher to ask some questions about her son.