Christmas in Spain

Here in Spain, Santa Claus' name is Papá Noel. But he didn't exist 20 years ago, so depending on the family, Papá Noel brings presents or he doesn't. At midnight on New Year's Day, the families are together and they eat the grapes (12 grapes, one for each chime of the clock's bell at 12 o'clock) Then, at about 1am, some young people (older than 13 years) go to a party called a "cotillón", that it which finishes at 6 am, more or less (depending on the age). On the night of The 5th of January, will come "los reyes magos" (the 3 Wise Men) come, so on the morning of the 6th, everybody will gets their presents.

Muchas grácias por la cuenta. A few points:

depender de = to depend on

We say "the fifth of January".  We write "5 January, 5th January or January 5"

When speaking about nouns as general ideas, we don't use "the" e.g. "families get together every Christmas" but "the families of my sisters and brothers get together".  

In the second case, we are talking about specific families and so we  use "the".

The word order of subject + verb does not change if there is a preceding relative clause (as in your last sentence).

There is a better way to say your second sentence: "Whether Santa brings presents or not depends on the family"

Bien hecho y feliz año nuevo, Michael