`but` in Spanish

but

1. conjunction
   • used to introduce a contrast
     
     pero

     I wanted to go, but I was tired. — Quería ir, pero estaba cansado.
2. preposition
   • [dated, rare], except; other than
     
     excepto

     No one but John came to the party. — Nadie excepto John vino a la fiesta.

     salvo

     No one but John came to the party. — Nadie salvo John vino a la fiesta.
3. adverb
   • [dated, rare], only; no more than
     
     solo

     He is but a child. — Él es solo un niño.

     tan solo

     He is but a child. — Él es tan solo un niño.
4. interjection
   • [informal, exclamatory], used to express surprise or objection
     
     ¡pero! [exclamatory]

     But that's impossible! — ¡Pero eso es imposible!