The use of could, would, or will be all imply future tense. The past tense version would be: You could not have made me happy, and I am convinced that I am the last woman in the world who could have made you so.
Can I use could instead of can?
Can, like could and would, is used to ask a polite question, but can is only used to ask permission to do or say something (Can I borrow your car? Can I get you something to drink?). Could is the past tense of can, but it also has uses apart from that--and that is where the confusion lies.
Can sentences examples in English?
Can sentence exampleCan you watch the house for me while Im gone? 1182. I can take care of myself. I can do it. You can spend it with a free conscience. Yes, can you believe the luck? I can handle it... now. But you can learn many things from books. You can know everything in the world and still make bad decisions.