In ¿Cuál es el verbo para “party” en español? we considered some possible translations for party as a verb. Among them: festejar, parrandear, salir (de copas/ de marcha/ de fiesta...) etc.
But what happens if we add the adjective "hard", as in the expression "party hard"? The literal translation for "hard" in Spanish would be "duro", but you won't use that in all context. For example, you would translate
You need to work hard to earn your wage
as "hay que trabajar duro para ganarse el sueldo". For
I have been working hard.
You may favor "mucho" instead of "duro". In addition
I am a hard working person
Would be translated as "Soy una persona trabajadora".
Just translating "hard" as "duro" could lead to may anglicisms in many contexts.
Thus said, what happens if we try to translate "party hard"? "Party hard" means to do the things you usually do at a party (dance, eat good food, drink alcohol, etc.) and to do them to excess, with intensity, etc.
But "festejar/parrandear/salir en exceso/excesivamente" don't really convey "party hard". It may convey frequency rather than intensity.
What if I wanted to translate for example
I like to work hard and party hard.
I like to work hard and party harder.
How could I translate "party hard"? Just simply "me gusta festejar/salir en exceso"?