What's a irregular verb. give a good explation

An irregular verb is a verb in which the past tense or past participle is not formed following the regular - ed, - d or - ied ending.

They are also known as strong verbs, and there are nine of them that happen to be the most commonly used word in the English language:

go-went (NOT goed). For example:" I went to the cinema last night."

get-got. For example: My son got a present at school today-

say-said. For example:" My teacher said something very interesting about our Constitution this morning."

see-saw. For example: "I saw a nice painting last weekend in the museum."

think-thought. For example: "I thought I had sent the e-mail, but it seems I forgot to do it."

make-made. For example:" I made a cake for my husband's birthday last Monday."

take-took. For example: "My sister took her dog for a walk yesterday at 4pm"

come-came. For example: "My parents came to visit me two weeks ago."

know-knew. For example: "I knew you were going to ask me about that"