1215 uses of prepositions "a", "de", and "en"

Question 1

a (to, at, in)

Answer 1

expresses direction toward a point in space or a moment in time
used to indicate:
-the time (hour) of the day
-after verbs of motion when followed by an infinitive, noun, or pronoun
-after verbs “empezar”, “comenzar”, “enseñar”, and “aprender” when followed by infinitive
-after verb “llegar”
-before direct object noun that refers to a specific person. also may be used to personify an animal or thing
If direct object is not a definite person, personal a is not used

Question 2

de (of, from, about, with, in)

Answer 2

indicates possession, material, and origin
used to indicate:
-to refer to a specific period of the day or night when telling time
-after the superlative to express in or of
-to describe personal physical characteristics
-as a synonym of “sobre” or “acerca de” meaning about

Question 3

en (at, in, on, inside, over)

Answer 3

in general situates someone or something within an area of time or space
used:
-to refer to a definite place
-as a synonym for "sobre" meaning on
-to indicate means of transportation