Perfect Tense Verbs The three perfect tenses are made up of the helping verb have and the past participle. The form of the helping verb shows the tense. Present Perfect Tense: Use this tense to express an action that took place at an indefinite time in the past. The action may still be going on. Example: Dr. Smith has conducted the research. Past Perfect Tense: Use this tense to express an action in the past that was completed before another action took place. Example: Dr. Smith had conducted the research before the year ended. Future Perfect Tense: Use this tense for an action that will be completed before another action took place. Example: Dr. Smith will have conducted the research before the year ends.

Try it out: What is the tense of the underlined verb in each of the following sentences, present perfect, past perfect, or future perfect? 1. Polio had threatened the lives of many people before a vaccine was discovered. ___________________________ 2. A vaccine protects a person from a disease before the disease has started. 3. Dr. Jonas Salk had already developed a successful vaccine when Dr. Albert Sabin produced an even more effective one. 4. Before long, other scientists will have tested new treatments.

Verb Present Perfect Past Perfect Future Perfect plant has planted had planted will have planted wipe has wiped had wiped will have wiped warn has warned had warned will have warned grin has grinned had grinned will have grinned decide has decided had decided will have decided dry has dried had dried will have dried toss has tossed had tossed will have tossed

Try it out: This story has eleven mistakes in the use of the perfect tenses. Identify and correct each mistake. My dad will have always hated shots. Since he was a young boy, he will have avoided them like the plague. Just from nervousness, he had dropped several pounds over the years. He will have even canceled appointments with his doctor. His new doctor, Dr. Mei, had warned him, though. When Dad goes for his next shot, he had conquered his fear --or else. Dr. Mei had reminded my dad of this showdown several times. As a consequence, my dad and mom has started trying to overcome my dad's fear. In the last two weeks, he will have watched several television programs about doctors and hospitals. Dad thinks that watching the programs had already helped him a little. We are all pretty confident that before his next visit, he has defeated his longtime fear of shots.

Progressive Tense Verbs The progressive forms are made up of a form of be and the present participle. The helping verb shows the tense. Present Progressive: We are studying plants in school now. Past Progressive: We were studying plants when the bell rang. Future Progressive: We will be studying plants for several days. Present Perfect Progressive: We have been studying plants for several days. Past Perfect Progressive: We had been studying plants for only a day when we had our field trip. Future Perfect Progressive: We will have been studying plants for weeks by the time our project is done.

Try it out: Write down the progressive form for each of the following sentences, then tell which form it is. 1. Just last summer, I was experimenting with sunflowers. 2. Joe had been talking about his sunflowers for years. 3. In school, he and I were also learning about plants. 4. My flowers have been growing all through the summer. 5. By August, I will have been tending the plants for four months. 6. He has been helping me with my crop. 7. Soon we will be eating sunflower seeds. 8. By next fall, I will have been producing sunflower seeds for three years.

1. write 2. learn 3. approach 4. hike 5. collect 6. gather 7. give Directions: Write a sentence using the following ten verbs in progressive forms. Label each verb phrase as present progressive, past progressive, or future progressive. Ex: finish I was finishing my homework when my mom called me for dinner. Past progressive 1. write 2. learn 3. approach 4. hike 5. collect 6. gather 7. give 8. assist 9. rest 10. listen