Showing Purpose between two clauses in english

This slide explain about the use of purpose conjunction

1. I turned off the TV so (that) my roommate could study in peace and quiet. EXPRESSING PURPOSE USING “ SO (THAT)” AND “ IN ORDER TO” I turned off the TV in order to enable my roommate to study in peace and quiet.

2. In order that has the same meaning as so that but is less commonly used. Example: I turned off the TV in order that my roommate could study in peace and quiet. Both so that and in order that introduce adverb clauses. It is unusual, but possible, to put these adverb clauses at the beginning of a sentence: So that my roommate could study in peace and quiet, I turned off the TV **Also possible but less common: the use of may or might in place of can or could: e.g., I cashed a check so that I might but my textbooks.

3. So ( expressing purpose) vs So ( expressing result) The use of modal auxiliary in the dependent clause signals “purpose” as opposed to “result” I wanted a college education, so I enrolled at the university. I wanted a college education, so (that) I could get a good job.