1. When indicating ability, we can use the third-person singular form of "can" to express this. For example, "He can swim." can be rewritten as "He can swim."2. When making a request or granting permission, we can also use the third-person singular form of "can." For example, "Can you pass me the salt?" can be rewritten as "Can you pass me the salt?"3. "Can" can also be used in the third person singular form to indicate possibility. For example, "There can be no solution." can be rewritten as "There can be no solution."4. When "can" is used as a noun, such as referring to containers, "cans" is the acceptable plural form. For example, "There are many cans on the table." can remain the same: "There are many cans on the table."