sad [sæd]
adjective
sadder (comparative)saddest (superlative)1 (unhappy) [+person, eyes, smile] triste
I'm sad that I won't be able to play football any more estoy triste porque no voy a poder volver a jugar al fútbol; me entristece no poder volver a jugar al fútbol
we were sad about or at the news of her illness nos entristeció or nos apenó enterarnos de su enfermedad
to become sad entristecerse; ponerse triste
to feel sad sentirse triste; estar triste
to grow sad entristecerse; ponerse triste
to be sad at heart estar profundamente triste; tener el corazón oprimido
to make sb sad entristecer or poner triste a algn
he left a sadder and a wiser man cuando se marchó era un hombre escarmentado
2 (distressing) [+story, occasion, loss] triste; [+news] malo; triste
it is my sad duty to inform you that ... tengo el penoso deber de informarle de que ...
the sad fact or truth is that ... la triste realidad es que ...
how sad! ¡qué triste!; ¡qué pena!
it is sad to see such expertise wasted es lamentable or da pena ver tanta pericia echada a perder
it was a sad sight era una triste escena
You should generally put triste after the noun when translating sad in the sense of "unhappy", and before the noun in the sense of "distressing":
He always seemed a sad little boy Siempre pareció un niño triste
... the sad reality ... ... la triste realidad ...