Prepositions

„Por” marks the cause, the route, what something happens through, or what's exchanged for what (because of, through, in exchange for). „Para” marks the purpose, the destination, or a deadline (for, in order to, by when).

„A” marks the direction of movement or a specific point of contact (where to, to whom). „En” marks the place something is or happens in (where, inside what).

„Con” is the plain preposition of company and instrument — who you're with, or what you do something with.

„De” marks origin, possession, or topic — where something is from, whose it is, what you're talking about.

„Sin” is the plain „without” — the absence of a thing or of company.

„Sobre” is physically „on top of” something (touching from above) or, figuratively, a topic — close to „en” but stresses the surface, not the inside.

„Contra” is opposition or physical contact against something — an opponent, an opposing side, or a surface something leans on.

„Desde” marks a starting point — since when, or from where, something goes on or begins. Unlike plain „de”, it stresses the continuity from that point.

„Durante” spans the whole duration of an action — something happens throughout that period, not just at one point.

„Entre” is „between” two points or „among” a group — a place, a time, or a relationship involving more than one side.

„Hacia” is a direction, not an arrival — movement toward something, or an approximate time („around”).

„Hasta” is an endpoint — how far, or until when, something goes. The mirror of „desde”.

„Según” cites the source of an opinion or a rule — whose view, or by what criterion.

„Tras” is a formal, one-word stand-in for both „después de” (after) and „detrás de” (behind) — more common in writing than speech.

„Ante” is a formal „before” — not physical position (that's „delante de”), but standing in the face of someone or something: a judge, a difficulty, a choice.

„Bajo” is „under” — physically (under the table) or figuratively (under pressure, under someone's control).

„Mediante” is a formal „by means of” or „through” — the means by which something gets done. Common in official writing and instructions, rare in speech.

„Vía” marks the route or channel something travels through — a place along the way, or the medium something is sent by (e.g. „vía email”).

„Versus” is a Latin loanword — it pits two sides against each other, mostly in sports, courts, and debates. Everyday speech usually reaches for „contra” instead.

„Cabe” used to mean „next to, beside” — today it's essentially extinct, found only in older literary texts. Modern Spanish uses „junto a” or „al lado de” instead.

„So” survives only in fossilized legal phrases, chiefly „so pena de” (under penalty of). Outside those fixed expressions it isn't used at all.