Final answer:
Granny gave something a swallo to check its flavor.
Step-by-step explanation:
In the given context, the phrase 'give something a swallo' is a figurative expression used to describe the act of tasting food. Granny gives something a swallo to assess its flavor, not because she wants to check its color, test its jump, or hear its sound. Tasting food helps us determine its taste, texture, and other sensory qualities and decide whether it is pleasant or unpleasant to consume.