My good friend is "Mi buen amigo" for a guy and "Mi buena amiga" for a girl. Normally adjectives come after the word. In this case, that would make your friends good as opposed to bad. And that's not the sense of what you want to convey.
¿Quieres ser mi amigo? (Being polite)
Seamos amigos (Including both the speaker and the listener)
Sé mi amigo.
*You can say "amiga" if the oher person is a woman.
Un amigo for a male, una amiga for a female.
Your friend is my friend will translate to 'su amigo es mi amigo' in Spanish.
El es mi amigo.
Say "Yo soy su amigo".
Mi mejor amigo(a) es...
Eres mi amigo
Eres mi buen amigo
You would say "estoy bueno, mi amigo/a".
Buenas noches, amigo (amiga).
To say hello friend in Spanish you can say "hola amigo".
Para mi buena amiga Teresa
In Spanish it sometimes matters if you are talking to or about a male or female. If you are saying 'good night my friend' to a female it is 'buenas noches mi amiga' instead of 'amigo.'
my friend = mi amigo
Bravo, mi amigo! Or: Un bueno, mi amigo!
Translation: Que tengas un buen dia amigo.
Eso esta bien parar saber amigo
If you're speaking to a close friend, you'd say, Es bueno que no estás trabajando.
amigo