Soutien vs. appui

While 'soutien' and 'appui' both translate to 'support' in English, they have subtle differences in usage and connotation in French.

Soutien

'Soutien' generally refers to moral, emotional, or personal support. It often implies a more personal or ongoing form of assistance.
Elle a reçu le soutien de sa famille pendant sa maladie.
(She received support from her family during her illness.)
Le groupe de soutien se réunit chaque semaine.
(The support group meets every week.)
Son ami lui a offert un soutien moral dans les moments difficiles.
(His friend offered him moral support during difficult times.)

Appui

'Appui' often denotes more concrete or tangible support, such as financial backing, political support, or physical reinforcement.
Le projet a reçu l'appui financier du gouvernement.
(The project received financial support from the government.)
Il cherche l'appui de ses collègues pour sa candidature.
(He's seeking the backing of his colleagues for his candidacy.)
Le mur a besoin d'un appui supplémentaire pour tenir.
(The wall needs additional support to stand.)

Summary

While both 'soutien' and 'appui' mean support, 'soutien' is more often used for emotional or personal support, while 'appui' typically refers to more concrete or institutional forms of backing. However, there can be overlap in their usage depending on the context.