Skill 4 : Past Participle

Past participle can cause confusion in the Structure  section of the TOEFL test because a past participle can be either an adjective or a part of the verb. The past participle is the form of the verb that appears with have or be, it often ends in -ed, but there also many irregular past participles in English

The mailman has left a letter in the mailbox.
The classes were taught by Professor Smith.

In the first sentence, the past participle left is part of the verb because it is accompanied by has.  In the second sentence, the past participle taught is part of the verb because it is accompanied by were.

A past participle is an adjective when it is not accompanied by some form  of be or have.

The letter left in the mailbox was for me.
The classes taught by Professor Smith were very interesting.

In the first sentence, left is an adjective rather than a verb because it is not accompanied by a form of be or have (and there is a verb), was, later in the sentence). In the second sentence, taught is an adjective rather than a verb because it is not accompanied by a form of be or have (and there is a verb, were, later in the sentence).

The following example shows how a past participle can be confused with the verb in the Structure section of the TOEFL test.

Example :
The bread....baked this morning smelled delicious.

1. has
2. was
3. it
4. just

 In this example, if you look only at the first few words of the sentence, it appears that bread is the subject and baked is either a complete verb or a past participle that needs a helping verb. But if you look further in the sentence, you will see the verb smelled. You will then recognize that baked is a participial adjective and is therefore not part of the verb. Answer (1) and (2) are incorrect because baked is an adjective ad does not need a helping verb such as has or was. Answer the (3) is incorrect because there is no need for the subject it. Answer (4) is the best answer to this question.

The following chart outlines the key information that you should remember about past participles.
"A past participle often ends in -ed, but there are also many irregular past participle. For many verbs, including -ed verbs, the simple past and the past participle are the same and can be easily confused. The -ed form of the verb can be (1) the simple past, (2) the past participle of a verb, or (3) an adjective"