Fröhlichen vierten Juli! or Fröhlichen Unabhängigkeitstag (=independence day)
Assuming you mean "how" to say happy in German, there are a couple of different ways: Froh and gluecklich.
happy fourth anniversary -- bon quatrième anniversaire de mariage
Happy Friday in German is glücklicher Freitag
Juli
happy - glücklich Also fröhlich, froh
In Pennsylvania German, you can say "Ei glickliche Geburdsdaag!" to wish someone a happy birthday.
I am not a happy puppy is an English idiom and cannot be translated into German in a way that conveys it's meaning.
happy married life = glückliches Eheleben
"Happy Saint Patrick´s Day" in German is: Fröhlichen St. Patricks Tag
Frohes Neues Jahr.
Die glücklichen Kinder.