ACTIVE AND PASSIVE VOICE

Active sentance ( active voice ) is a sentace where the subject is doing a job. In contrast, passive sentaces ( passive voice ) is a sentace where the subject was subjected to the job by the object of the sentance. Active voice is usually used in daily life compared with the passive voice. However, we always find the passive voice in news papers, articles in magazines and scholarly writings. Passive voice is used because the object of the active voice is more important than the subject.
for example:
a. active: Bob mailed the package
b. passive: The package was mailed by Bob
# a and b have the same meaning
c. Bob mailed the package
The package was mailed by Bob
# in c the object ( the package ) of an active sentance becomes the subject of the passive sentance
d. Bob mailed the package
The package was mailed by Bob
# In d the subject (Bob) of an active sentace is the object of "by-phrase" in a passive sentance.
e. active: the teacher corrects our homework.
f. passive: Our homework is corrected by the teacher
g. active: Mr. Lee will teach this class
h. passive: This class will be taught by Mr. Lee
# Form of all passive verb:
BE + PAST PARTICIPLE
BE can be in any of its forms: am, is, are, was, were, has been, have been, will be, etc. THE PAST PARTICIPLE follows BE. For regular verbs, the past participle ends in -ed ( e.g., mailed, corrected ). Some past participles are irregular ( e.g., taught )