The vast majority of English verbs are regular in pattern, adding the suffix -ed to the stem of the verb, or just -d if the stem already ends with an e.
show > showed inflate > inflated
English shows its Germanic heritage in the fact that most of the commonly used verbs (an the oldest verbs in the language) follow the Germanic system of changing the vowel in the stem to indicate a change of tense. This is exactly the same as in Dutch sterke werkwoorden.
sing > sang > has sung zingen > zang > heeft gezongen
There are really only 2 irregular verbs in English (to be and to go). This is because both verbs are a combination of forms from two different verbs:
to be = Old English beon and wesan to go = Old English gan and wendan
Other than that tiny complication, English is easy!
Follow this link to a list of the main strong verbs in English: