All sentences must have a verb. Verbs are either words that express being or action.
This is Mary. She plays football.
Verbs change form related to
Simple present tense: Something that happens regularly.
She plays football every day. She always brings her own ball.
Present continuous tense: Something that happens right now or today, or will happen later.
She is playing football now. She is playing football tomorrow too.
Simple past tense: Something that happened yesterday or earlier.
Yesterday we played football together. Mary brought her ball this morning.
Present perfect tense: Something that has happened.
They have played football today. She has brought her football every week.
Infinitive Present Simple past Present perfect
Regular to play play / plays played played
Irregular to be am / are / is was / were have / has been
Irregular to bring bring / brings brought brought