Usos de Las Preposiciones A, De y En

A

A means to, at or in and denotes movement toward a place or a moment in time.
• indicate time of day
A las nueve yo miro TV.
• used with infinitive verbs when they follow verbs of motion.
venimos a pescar
• used with infinitive verbs when they follow aprender, comenzar, empezar and enseñar.
• always after the verb llegar
• personal A, it is used before a direct object noun that refers to a specific person or to an animal or thing you treat like a human.

De

De means of, from, about, with and in. It is used to refer to possession material and origin.
• Used to refer to a period of time like morning or afternoon.
de la mañana
• Used after a superlative to mean in or of.
más...de
• Physical Characteristics
• Can be used in place of sobre or acerca de to mean about.

En

En can mean at, in, on, inside and over. It places a person or thing within an area of time or space.
• Refers to a definite place.
Esta en mi casa.
• Can be used in place of sobre to mean on.
• Indicates means of transportation.