2.  Within a sentence a shift is a change from one subject to another or from one verb to another. Often shifts are acceptable because they are necessary to express the meaning the writer intends.  The smoothness of a sentence is affected by an unnecessary or awkward shift.

3.  Awkward:  A student should choose books from the reading list so that you can be sure they are acceptable to the teacher.  (The unnecessary shift from student to you is awkward is confusing)

4.  Acceptable:  A student should choose books from the reading list so that he or she can be sure they are acceptable to the teacher.

5. A person should always do A. No Change their best in all areas of B. there life. C. his or her D. them C. A person should always do his or her best in all areas of life.

6.  Changing without reason from one tense to another within a sentence creates an awkward and confusing effect. Stick to the tense that you start with unless there is an excellent reason for changing.

7.  Unnecessary shift-At this point the President reads (present tense) a prepared statement but refused (past tense) to answer any questions.

8.  Shift avoided-At this point the President read (past tense) a prepared statement but refused (past tense) to answer any questions.  Shift avoided-At this point the President reads (present tense) a prepared statement but refuses (present tense) to answer any questions.

9. The teacher gives great lessons, A. No Change but she teaches even better. B. teach C. taught D. teached A. Teacher gives and teaches both represent the present tense.

10.  The term “person” identifies whether the speaker of a sentence is the person speaking (the first person), the person spoken to (the second person), or the person spoken about (the third person).

11.  Inconsistent-A person who is a nonsmoker can develop lung troubles when you live with smokers.

12.  Third person-A person who is a nonsmoker can develop lung troubles when he or she lives with smokers.  Second person-If you are a nonsmoker, you can develop lung troubles if you live with smokers.

13. When you walk across the A. No Change street, a person should look B. he or she both ways. C. they D. you D. The word “you” is second person, so the sentence should remain second person- you.

14.  Pronouns should agree in number with the nouns they replace. You can avoid shifting number and confusing readers by maintaining a clear plural or singular sense in all significant words throughout a sentence.

15.  Inconsistent:  They had the best time of their life.

16.  Revised:  They had the best time of their lives.

17. Yesterday, we had the A. No Change one opportunity to change B. I my outfit. C. she D. her B. My represents one person, so I would be the correct way to finish the statement.