Which sentence is not in the future tense?

The sentence "She ate dinner" is in the past tense, which clearly differentiates it from the future tense used in the other options. In future tense, the construction typically involves the auxiliary verb "will" followed by the base form of a verb, indicating actions that will occur later. For example, the other sentences exemplify future actions: "I will go," "He will eat," and "They will play." In contrast, "She ate dinners" uses the simple past form of the verb "eat," indicating that the action has already happened rather than something that will happen. Understanding verb tenses is crucial in identifying the timing of actions in sentences.