Answer:.
1. If we__had___ a yacht, we_could sail_ the seven seas. (have, sail)
2. If he__had___more time, he__could learn___karate. (have, learn)
3. If they__told___ their father, he __would be__very angry. (tell, be)
4. She__could spend____ a year in the USA if it_were__ easier to get a green card. be= subjunctive case
5. If I_were to live_ on a lonely island, I_would run___ around naked all day. (Subjunctive)
OR If I lived... I could run around...
6. We_would help___ you if we_knew__ how. (help know)
7 My brother _would buy____a sports car if he_had_ the money. (buy, have)
8. If I felt___better I __would go____the cinema with you. (feel, go) or If I feel better, I will go to the cinema with you.
9. *If you_went_by bike more often, you _ would not be_so flabby. (go, not be) OR If you were to go by bike...
10. She_would not talk___to you if she_were_ mad at you. (not talk, be) (another subjunctive case example
Explanation: In general, use a conditional modal/auxiliary with the verb in the main clause. The verb in the "If-clause" will be in the (rare) subjunctive case, or in the past tense form of the verb.