If means “si” in French, and there are certain sequences of tenses that are needed afterwards.
si clause
result clause
si + present
present / future / imperative
Si j’ai assez de temps, j’irai en ville.
If I have enough time, I will go to town.
si clause
result clause
si + imperfect
conditional
Si j’avais assez de temps, j’irais en ville.
If I had enough time, I would go to town.
si clause
result clause
si + pluperfect
(contrary to past facts)
past conditional
Si j’avais eu assez de temps, je serais allé en ville.
If I had had enough time, I would have gone to town.
A votre tour / your turn
If she has enough holidays, she will go to Spain.
If she had enough holidays, she would go to Spain.
I she had had enough holidays, she would have gone to Spain.
SOLUTION
Si j’ai assez de vacances, j’irai en Espagne.
Si j’avais assez de vacances, j’irais en Espagne.
Si j’avais eu assez de vacances, je serais allé en Espagne.