Active / Passive Verb Forms
Sentences can be active or passive. Therefore, tenses also have "Active Forms" and "Passive Forms". You must learn to recognize the difference to successfully speak English.
ACTIVE FORM
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.
[Thing doing action] + [VERB] + [thing receiving action]
EXAMPLES:
The professor teaches the students.
(subject) (active verb) (object)
(doing action) (receiving action)
John washes the dishes.
(subject) (active verb) (object)
(doing action) (receiving action)
PASSIVE FORM
In some sentences, speakers use the passive form. In the passive form, the thing receiving the action is the subject of the sentence and the thing doing the action is optionally included at the end of the sentence. You can use the passive form if you think the thing receiving the action is more important or should be emphasized.
[Thing receiving action] + [BE] + [past participle of verb] + [by] + [thing doing action]
EXAMPLES:
The students are taught by the professor.
(subject) (passive verb)
(receiving action) (doing action)
The dishes are washed by John.
(subject) (passive verb)
(receiving action) (doing action)