You convert a sentence in the present tense to a sentence in the past tense by simply changing the verb form to the past tense. You converted a sentence in the present tense to a sentence in the past...
Use the past tense of the verb in the sentence you are converting. For instance, to change the present tense sentence "I walk home every day," I simply change walk to its past tense form, walked:...
Our is a possessive determiner - not a verb- it can be used in past or present sentences. It is not past or present . They saw our dog on the road. They see our mother everyday.
The word "is" is present tense.
does is present tense, does is the third person singular form of do. You use does for he/she/it or singular noun subjects. He does his homework every night. She does...