Past Past Continuous Present Perfect Present Perf. Past Perfect Past Perfect Cont. Simple Future Future Continuous Future Perfect Future Perfect Cont. You must learn to recognize the difference to successfully speak English. In active sentences, the thing doing the action is the subject of the sentence and the thing receiving the action is the object.
Most sentences are active.
The professor teaches the students. John washes the dishes. In some sentences, speakers use the passive form. In the passive form, the thing receiving the action is the subject and the thing doing the action is the object. You can use the passive form if you think the thing receiving the action is more important or should be emphasized.