Which type of projection is best for sorting nations by language?

Cylindrical map projections

Explanation:

Cylindrical map projections are used for portraying the Earth. Cylindrical map projections are rectangles, but are called cylindrical because they can be rolled up and their edges mapped in a tube, or cylinder. They have straight coordinate lines with horizontal parallels crossing meridians at right angles. All meridians are equally spaced and the scale is consistent along each parallel. The only factor that distinguishes different cylindrical map projections from one another is the scale used when spacing the parallel lines on the map.

Cylindrical map projections are great for comparing latitudes to each other and are useful for teaching and visualizing the world as a whole, by determining continents, languages, etc but really aren’t the most accurate way of visualizing how the world really looks in its entirety.