estuvieron comenzando
-they/you were beginning
Preterite progressiveellos/ellas/ustedesconjugation ofcomenzar.

comenzar

Después de dos entradas de juego, los aficionados estuvieron comenzando a sacudir su cabezas por el hecho que este podría ser la tercera gran sorpresa del campeonato.
After two innings of play, fans were beginning to get their head around the fact that this could the third huge upset of the championship.
Word of the Day
to bake