Joyeux Anniversaire!
Happy Anniversary in French is "Joyeux anniversaire"
Fa'amanatuga fiafia (fa'amanatuga/anniversary - fiafia/happy)
the translation in french is : 'sois heureux'
Actually, we don't have the exact equivalent translation to "Happy Anniversary" as the word "anniversary" contains a lot of uncertainties (such as anniversary for marriage? anniversary for important festival?......) But anyway, I could still offer you the direct word-to-word translation of "Happy Anniversary", which is "周年纪念日快乐". Hope this won't disappoint you ;)
happy fourth anniversary -- bon quatrième anniversaire de mariage
The translation of happy into French is "heureux." While the translation of landings into French is "débarquements." Since all adjectives go after the noun in French, except for a certain few, the translation of "happy landings" would be "débarquements heureux."
joyeux anniversaire a vous
happy twenty ninth anniversary = joyeux anniversaire pour tes 29 ans
Bon Septième anniversaire
Joyeux trentième anniversaire.
joyeux troisième anniversaire
Heureux quinzième anniversaire.