The purpose of this unit is to help students who sometimes drop the -d or -ed endings on regular verbs and the adjectives made from them.

First you need to be able to distinguish between regular and irregular verbs. If a verb is regular, its past tense and past participle are formed by adding -d or -ed to the base verb. For example:

If a verb is irregular (in other words, not regular), it does not follow this nice, easy pattern of adding -d or -ed. For example, give is an irregular verb. Here are its three main forms:

You’re already familiar with base verbs and past tenses, but the term past participle might be new to you. What does it mean? The past participle is the form of a verb that is used with helping verbs such as have, has, or a form of the verb to be when it is used to make the passive voice. (See Chapter 4 if you need to review the definition of passive voice). These examples show how the presence of a helping verb signals the need for a -d to be added to the regular verb purchase:

(a) I have purchased the suit.

(b) She has purchased the apartment building.

(c) He had purchased the license only thirty minutes before the wedding.

(d) The tainted medicine was purchased in a drug store two miles from the victim’s home.

(e) Fourteen square acres in the middle of the city were purchased by an international corporation.

The three trouble spots

When writers drop -d and -ed endings, they drop them on past tense verbs, past participles, and adjectives that are derived from verbs. Of these three trouble spots, the first—past tense—is the easiest to catch. The other two are more challenging. Study these correct examples:

(a) Yesterday the doctor prescribed a basic blood pressure medicine for Carl. (past tense)

(b) Another specialist has prescribed treatment for him on several occasions. (past participle)

(c) The prescribed pills were very effective. (adjective derived from a verb)

You can probably see why most students would have the least difficulty with (a). The word Yesterday is a context clue for the past tense, and that helps the writer remember to add the -d to prescribe.

In (b) and (c), there are no obvious context clues for the past tense, but there are other clues for the student who’s wondering whether to use a -d. The clue in (b) is the helping verb has. And sometimes, as you’ll see in the exercises, a sentence contains more than one helping verb. For example, you’ll see sentences with longer verb phrases, such as this one:

A third doctor might have prescribed something else.

In (c) the clue is the noun pills. Someone did the act of prescribing the pills, and now they can be described as prescribed. Adjectives that are made from regular verbs end in -d or -ed.

In this set of three examples, add -d where it belongs and, each time, make a note of why you added it:

1. Sharon had change tremendously since high school.

2. After the birth of his first child, Gregory was a change man.

3. We change our phone number after a few crank calls.

1. verb phrase; 2. adjective; 3. past tense