A preposition is a word that links elements and shows the relationship between a noun, a pronoun, or a noun phrase and another element of the sentence. It usually introduces a complement and does not function alone as the predicate core. In Spanish, prepositions do not change form. Using the correct preposition changes the meaning or intention of the sentence.

In indicates location, position, or a general time frame. It is used to say where something or someone is and to talk about months, years, and parts of the day. It does not equal inside in all contexts. It can also indicate a means of transportation without an article.

To indicates direction, destination, or movement toward a place. It is also used with some times to indicate exact time. In Spanish, to introduces the direct object of a person or animate being in the general 'a personal' construction. It does not express a fixed location, but movement or an arrival point.

From indicates origin, possession, material, or content. It is the basic preposition to say where someone or something comes from. It is used to describe the contents of a container or the topic of a book. It also appears in many fixed expressions in Spanish.

With expresses companionship, means, or instrument. It is used to say with whom someone is and with what something is done. It can also indicate mood or manner. In many phrases it is equivalent to using or with in English, but its placement follows Spanish word order.

For indicates cause, motive, exchange, means, and route. It is used to explain the reason for something and to talk about prices or changes. It also appears with means of communication and transportation in certain contexts. In routes or journeys, it is usually translated as through or along.

To indicates purpose, recipient, deadline, and intended direction. It is used to state the purpose of an action and for whom something is for. It also marks a deadline or a projected date. It contrasts with for when differentiating goal (for) from cause or means (by).

In is used for location and to is used for destination or movement. The choice changes depending on whether the idea is to be in a place or to go toward a place. With movement verbs, to tends to appear. With verbs of permanence or state, in tends to appear.

From indicates origin or starting point as a general trait. From is used to mark the starting point of movement or a period of time. From typically appears with a destination or with hasta to indicate a stretch. From appears more with nationality, origin, and belonging.

Some expressions require a specific preposition by convention. Changing the preposition can sound odd or change the meaning. Memorizing these combinations helps you speak naturally. Many go with de, a, or con depending on the verb or noun.