Comunícate Conmigo: Parte dos 1ed (CCP2L08) p136-

Pay attention to Spelling changers verbs -car, -gar, -zar, -guar, 'iuir, -ger-gir / -cer-cir / verbs with irreg. YO in present tense / DISHES: Dar, Ir, Ser, Haber, Estar, Saber / stem-changers -ar-er / stem-changing -ir /