Yahoo: Could our universe exist because black holes ate up all the antimatter? Could our universe exist because black holes ate up all the antimatter? “Would” is used for hypotheticals and future possibilities that may not occur.

Understanding the Context

“Should” implies advice, expectation, or probability. “Could” expresses past ability or present possibility. First of all, ‘would’ is a modal auxiliary verb and is the past tense form of ‘will.’.