Partir vs. s'en aller

 

Partir and s'en aller are synonyms but they carry different connotations. First off, it seems to me that s'en aller belongs to a more familiar register of French.

Je m'en vais. -- I'm off. / I'm out of here. / I'm leaving.

In the imperative, va-t-en means "get out!" in a rather rude way.

Je pars au vacances. -- I'm leaving for vacation. You could not say Je m'en vais au vacances.

Hi Frank, 

Just to add to what Chris said, we would not use s'en aller for holidays.

partir en vacances/en weekend