The word “open” is typically used in its present tense form to mean “to make or become open,” such as “I am going to open the door.” However, it can also be used in its past tense form to mean “opened,” as in “The store opened at 9 a.m.” The past tense of “open” is formed by adding “-ed” to the present tense form, so the correct past tense form would be “opened.
