What is the verb tense in the sentence 'They walked home from school today'?

The sentence "They walked home from school today" is in the past tense because it describes an action that has already occurred. The verb "walked" is the past tense form of the verb "walk." Past tense is used to indicate that the action of walking took place before the current moment in time, aligning with the use of "today" to refer to events that are completed within that day.

In this context, the focus is on the specific action of walking that happened earlier in the day. This indicates that the event is not ongoing or planned for the future, which would be characteristics of other tenses. Therefore, the correct identification of the verb tense as past is based on the clear indication that the action is performed and completed prior to now.