Simple Syrup.

If you want to sweeten a cold beverage (lemonade, iced coffee, whatehaveyou), regular granulated sugar will not dissolve effectively.

Some people ask for their iced coffee with the sugar melted…that is, they put the sugar in and essentially make an adhoc simple syrup with hot coffee instead of hot water, then fill with ice and chilled coffee.

I personally think that’s disgusting, because that automatically waters down the coffee. I’d rather have any of the flavor “shots” they offer, which is essentially just simple syrup plus flavor.

Or I’d just get artificial sweetener, because most of them dissolve better in cold beverages than regular sugar.