WARNING! Spoilers ahead, read the following information, at your own risk.
There are several spells used by witches (and ogres,) in the Human World. In magical world, it is not a requirement to say the name of a spell aloud; however, it is vital to do so in the Human World - because they won't be able to use magic, otherwise.
Agrandissement: This can be translated as 'aggrandising' or 'expansion' in English and Chocolat uses this, especially in the earlier chapters in the manga, to make things larger.
Attraper: In English, it can be called 'catcher' or 'trapper'. It is only use once, when Chocolat transforms the heart-shaped hairpin - into a key, to open her mother's diary.
Le Cercle du Cœur: In English, it can be translated as 'The circle of the heart'.
Galaxie Ambre: The English translation for this spell is 'amber galaxy.' Amber uses this spell in the very last chapter of the manga (Chapter 43.)