How could you verify that a soft drink container contains diet rather than sweetened?

Check the nutritional information label: Diet soft drinks will have zero calories and zero grams of sugar listed in the nutrition facts panel, while sweetened soft drinks will have calories and sugar content.

Taste test: Diet soft drinks are typically sweeter than sweetened soft drinks due to the use of artificial sweeteners.

Look for the word "diet" or "sugar-free" on the label: Diet soft drinks will typically have the word "diet" or "sugar-free" prominently displayed on the front of the container.

Check the color of the label or cap: Some soft drink brands use different colors to distinguish between diet and sweetened drinks. For example, Diet Coke is often sold in a silver can, while regular Coke is sold in a red can.

Look for a "no added sugar" claim on the label: This claim means that the drink does not contain any added sugars, including artificial sweeteners.