In this PPT you will find: *13 slides with a clear grammatical explanation about this topic. *This is a bilingual presentation in English and Spanish. It has been recorded by a native Spanish speaker. You can use this presentation with or without audio. *This presentation has audio, smooth transitions and very appropriate pictures for the class. *This PPT can be used as a regular presentation or can also be printed as a handout for the students. (full page, half page, or 6 slides in one sheet of