In a medium saucepan, combine sugar and water. Cook on low flame stirring until the sugar dissolves. Turn off the heat once the sugar dissolves. Let it cool for about 10~15 minutes.
Stir in the freshly squeezed lemon/ lime juice and mix well to combine. Let it cool completely. Store in a clean bottle and refrigerate until ready to use.
To make the lemonade: Combine 1 part lemonade concentrate to 2 parts water and swerve chilled over ice.