📅 Created: 15 Jun, 2023
🔄 Updated: 23 Aug, 2025

You’ve been traveling all day. You ___ be very tired ?

Explanation

In the sentence "You’ve been traveling all day. You ___ be very tired," the use of the modal verb "must" conveys a strong logical conclusion or assumption based on the situation described. Since the person has been traveling all day, it is reasonable to deduce that they would feel exhausted. "Must" implies a high degree of certainty; the speaker believes that it is almost a given that the traveler is tired, given the circumstances.

Conversely, the other options do not fit the context as well. "Can't" suggests impossibility, implying that the traveler is not tired, which contradicts the logical inference from their long day of travel. "Might" indicates a possibility but lacks the certainty needed in this context, leaving room for doubt. Lastly, "ought to" implies a recommendation or responsibility rather than a conclusion about the traveler’s state. Hence, "must" is the most appropriate choice here, emphasizing the speaker's strong belief in the weariness of the traveler after a long day.