Using "Could" in Present, Past, and Future Most modal verbs behave quite irregularly in the past and the future. Study the chart below to learn how "could" behaves in different contexts. Modal Use Positive Forms 1. = Present 2. = Past 3. = Future Negative Forms 1. = Present 2. = Past 3. = Future You can also use: could possibility 1. John could be the one who stole the money.2. John could have been the one who stole the money. 3. John could go to jail for stealing the money. 1. Mary couldn't be the one who stole the money.2. Mary couldn't have been the one who stole the money. 3. Mary couldn't possibly go to jail for the crime. might, may could conditional of can 1. If I had more time, I could travel around the world.2. If I had had more time, I could have traveled around the world. 3. If I had more time this winter, I could travel around the world. 1. Even if I had more time, I couldn't travel around the world.2. Even if I...