Correct the following sentences, is the verb regular or irregular?
a. Johan breaked the window with a ball.
b. We buyed some science fiction books.
Paula studyed very hard, while she failed the test.
d. Did Camila went to the supermarket?
e. Melissa didn't understood the lesson.
f. What were your favorite toy when you was a child?
g. Jaime found her keys, but he couldn't opened the door.
We travel to Santa Marta last holiday.
i. Do Carlos built the house?
j. When you began to studyed?