Here are all the one-letter words in Spanish:
A — the preposition meaning “to” or “at.” Used to indicate direction, destination, time, or introduce indirect objects. (Voy a casa — I’m going home; a las tres — at three o’clock; le doy el libro a María — I give the book to María.)
Y — the conjunction meaning “and.” Used to connect words, phrases, or clauses. (pan y agua — bread and water.) Note: when the following word begins with the i sound, y changes to e to avoid the repeated sound (padre e hijo — father and son).
O — the conjunction meaning “or.” Used to present alternatives. (café o té — coffee or tea.) Similarly, when the following word begins with the o sound, o changes to u to avoid confusion (siete u ocho — seven or eight).
E — an alternate form of y (and), used only when the next word starts with the i sound. It is not an independent word on its own — it only appears as a substitute for y in that specific context.
U — an alternate form of o (or), used only when the next word starts with the o sound. Same situation as e — a positional substitute rather than a standalone word.
Those are all of them. Spanish has remarkably few — just three truly independent single-letter words (a, y, o), and two that only appear as phonetic alternates of two of those three.
Examples
A — “to / at”
- Voy a la iglesia. — I am going to the church.
- Hablo a las personas. — I speak to the people.
- Llevo la Biblia a los niños. — I bring the Bible to the children.
Y — “and”
- Oro y leo la Biblia cada día. — I pray and read the Bible every day.
- El amor y la fe son importantes. — Love and faith are important.
- Canto y predico en el pueblo. — I sing and preach in the village.
O — “or”
- ¿Tienes una Biblia o un himnario? — Do you have a Bible or a hymnal?
- Podemos orar o cantar juntos. — We can pray or sing together.
- ¿Vienes el lunes o el martes? — Are you coming Monday or Tuesday?
E — “and” (before words starting with i)
- Fe e iglesia van juntas. — Faith and church go together.
- El misionero habla de paz e igualdad. — The missionary speaks of peace and equality.
- Dios da gracia e iluminación. — God gives grace and illumination.
U — “or” (before words starting with o)
- ¿Siete u ocho personas vinieron hoy? — Did seven or eight people come today?
- ¿Es pecado u obediencia? — Is it sin or obedience?
- ¿Hablas u oras primero? — Do you speak or pray first?