Grammar:

Today I studied mixed conditionals. http://www.englishpage.com/conditional/mixedconditional.html

Then I did the exercises.
2.a. Tom is not going to come to dinner tomorrow because you insulted him yesterday.2.b. But, he (come) would be coming if you (insult) had not insulted him.
3.a. Marie is unhappy because she gave up her career when she got married. 3.b. But, Marie (be) would be happy if she (give, not) had not given up her career when she got married.
4.a. Dr. Mercer decided not to accept the research grant at Harvard because he is going to take six months off to spend more time with his family. 4.b. But, Dr. Mercer (accept) would have accepted the research grant at Harvard if he (take, not) were not going to take six months off to spend more time with his family.
5.a. Professor Schmitz talked so much about the Maasai tribe because she is an expert on African tribal groups. 5.b. But, Professor Schmitz (talk, not) would not have talked so much about the Maasai tribe if she (be, not) were not an expert on African tribal groups.
6.a. I am unemployed because I had a disagreement with my boss and I was fired. 6.b. But, I (be, not) would not be unemployed if I (have, not) had not had a disagreement with my boss and I (be, not) had not been fired.
7.a. Nicole speaks Chinese fluently because she lived in China for ten years. 7.b. But, Nicole (speak, not) would not speak Chinese fluently if she (live, not) had not lived in China for ten years.
8.a. I will not help you study for your test because you have spent the last two weeks partying and wasting time. 8.b. But, I (help) would help you study for your test if you (spend, not) had not spent the last two weeks partying and wasting time.
9.a. Eleanor and Ben are not going skiing with us this year because Eleanor just had a baby. 9.b. But, Eleanor and Ben (go) would be going skiing with us this year if Eleanor (have, not, just) had not just had a baby.
10.a. I am completely exhausted, so I will not go with you to the movies tonight. 10.b. But, if I (be, not) were not completely exhausted, I (go) would go with you to the movies tonight.
11.a. She is not worried about the conference tomorrow because she is not giving a speech. 11.b. But, she (be) would be worried about the conference tomorrow if she (give) were giving a speech. 12.a. Frank is not going to the graduation ceremony because he broke his leg snowboarding last week. 12.b. But, Frank (go) would be going to the graduation ceremony if he (break) had not broken his leg snowboarding last week.
13.a. They are not releasing the prisoner next month because there was so much public opposition to his parole. 13.b. But, they (release) would be releasing the prisoner next month if there (be) had not been so much opposition to his parole.