Here are some very interesting expressions with the preposition “a”. Check them out!

A Dios rogando y con el mazo dando – being a hypocrite
A grandes rasgos – in outline, broadly speaking
A ojo de buen cubero – by rule of thumb
A otro perro con ese hueso – Go try that on somebody else.
A perro flaco, todo son pulgas – It never rains, but it pours.
A rajatabla – strictly, to the letter
A río revuelto, ganancia de pescadores. – It’s good fishing in troubled waters.
Al pie de la letra – literally
Andar a gatas – to crawl, to go on all fours
Andar a la pesca de algo – to be looking for something
Comer a dos carrillos – to devour, to gobble up
Despedirse a la francesa – to leave without saying goodbye.
Echar pelillos a la mar – to make up, become friends again
Estar a partir un piñón – to be bosom pals
Llover a cántaros – to pour with rain
Mandar a paseo – to tell somebody to get lost
Reír a carcajadas – to roar with laughter
Saber a la perfección – to know something perfectly
Vérsele a uno el plumero – to know what someone is up to
Vivir a cuenta de alguien – to live off somebody
Vivir a cuerpo de rey – to live like a king
Zapatero, a tus zapatos. – Mind your own business.

Nos vemos prontito!