Breakdown of Mis abuelos, que tienen ochenta años, todavía bailan.
tener
to have
el año
the year
mi
my
el abuelo
the grandfather
Questions & Answers about Mis abuelos, que tienen ochenta años, todavía bailan.
Why is que used here instead of quienes for 'who'?
In Spanish, que is the most common relative pronoun and is used for both people and things. While you could perfectly well use quienes here because the phrase is set off by commas, que is much more common in everyday speech, even when referring to people as the subject of the clause.
Do the commas around que tienen ochenta años actually change the meaning?
Yes, significantly! The commas make this an explanatory clause. It means you are talking about all of your grandparents and just adding the extra fact that they are eighty. Without the commas, it would restrict the meaning, implying you have other grandparents of a different age and are only referring to the 80-year-old ones.
I always want to translate 'are eighty' with a form of ser or estar. Why is it tienen?
It is a classic trap to translate 'are' directly from English, and it is easy to slip up even at the B2 level. Remember that in Spanish, people 'have' years rather than 'are' years, so you must always use tener to express age.