* It's often used as a noun: "I took a bath."
* It's sometimes used as a transitive verb meaning "to wash" "I bathed the baby." In this case, the tenses work like other verbs:
* Present: I bathe the baby.
* Past: I bathed the baby.
* Future: I will bathe the baby.
However, "bath" is not typically used as a verb in the sense of "to immerse oneself in water." For that, we use the verb "bathe":
* Present: I bathe every day.
* Past: I bathed yesterday.
* Future: I will bathe tomorrow.