PERFECT TENSES

(ACTIVE VOICE, AFFIRMATIVE FORM)

to have + Participle II (V₃)

Present Perfect Tense (Active Voice)	have + V₃ has	You have written a book. She has written a book.
Past Perfect Tense (Active Voice)	had + V₃	They had written a book.
Future Perfect Tense (Active Voice)	shall have + V₃ will have	I shall have written a book. This doctor will have written a book.

Ex.5. Read and translate the following sentences:

1. Certain vitamins have contributed to the production of blood cells, hormones, genetic material, and chemicals of the nervous system. 2. Research works of many scientists have helped to estimate the cause of this disease. 3. Dentists had not determined the cause of the pain by 5 p.m. 4. Tomorrow they will have filled in the case history. 5. The surgeon has already extracted the wisdom tooth.

MODAL VERBS

SHOULD and WOULD

Ex.6. Read the following grammar material:

Should and Shouldn't - Use We use should and shouldn't to give advice or to talk about what we think is right or wrong.

You should means something like I think it is a good idea for you to do it.

You shouldn't means something like I think it is a bad idea for you to do it.

Should is used to express the opinion of a speaker and often follows I think or I don't think.

Examples:

You look tired. I think you should take a few days off.

Alice works very long hours. She should to talk to her boss.

- I have an English test tomorrow.

- I shouldn't worry if I were you. You have worked really hard.

Should - Quick Grammar Note

- To give advice to someone you can also say:

I should do it if I were you.

I shouldn't be so rude, if I were you.

- When you regret not doing something in the past, you can say:

I shouldn't have spoken to him like that.

I should have apologized earlier.

Would and Wouldn’t

Would can be used in some forms that are viewed as more formal or polite:

Examples:

"I would like a glass of water" compared with "I want a glass of water"; and "Would you get me a glass of water?" compared with the bare "Get me a glass of water."