Why Spanish has question and exclamation marks at the start of sentences

Spanish is the only language in the world which puts an ‘upside down’ exclamation mark (¡) or question mark (¿) at the start of a sentence. ¿Por qué? (why?), we ask.

Why Spanish has question and exclamation marks at the start of sentences
Spanish is the only language in the world which puts an ‘upside down’ exclamation mark (¡) or question mark (¿) at the start of a sentence. ¿Por qué? (why?), we ask.