Un, an easy way to tell is through the ending vowel. The 'o' in boligrafo is masculine, so the there are two automatic answers brought forward, 'un', and 'el'. Then, in english, it would be like saying 'the' or 'a' whereas the is either 'el' or 'la', while a a 'un' or 'una' respectively.
1. Ten paciencia 2.Ven rápido 3.Di la verdad 4.ponte tu cinturón de seguridad 5.sal temprano de la casa 6.has la tarea 7.se bueno (I’m not sure for 8 lol)
