1. Pon las decoraciónes en la pared.
2.Limpia el Baño
3. Vete a tu cuarto.
4.Sé un buen estudiante.
5. Busca por ellos en el centro commercial.
A rough translation would be sammy had 5 years, but it really just means sammy is 5 years old
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.