Respuesta :
They are called boot verbs because only yo, tú, el(la) and usted, ellos(as) and ustedes change while nosotros(as) and vosotros(as) dont change
Because if you draw a diagram of the yo,tú,etc. And then make a bubble around the ones that change it looks like a boot. Hence the name boot verbs, only the ones in the bubble change. Hope I didn't confuse you.