English verbs have the base form, the simple past and the past participle.
For most of the verbs (regular verbs),
the simple past and the past participle are spelled the same and are created by adding -ed to the base form.
However, there are many irregular verbs in English language which do not match to this pattern. Those verbs are mostly unpredictable, it is hard to derive them on the fly as you talk.
There are some patterns among them (spring-sprang, drink-drank,...), (blow-blew, know-knew,...)
but it is still hard to use those patterns as rules.
The only way to learn irregular verbs is to have memorized them one by one.