The phrase : "Ella le escribe a él" is not ok, the use of the pronoun and the subject is repetitive. It should be: "Ella le escribe" or "Ella escribe a él" The words "me, te, le, les, los, la, las" substitute the subject nouns of the sentence.

In Spanish, the pronouns you mentioned tend to appear together with the complement they refer to. -*Ella escribe a él is incorrect, -Ella le escribe a él is correct. If instead of "él" (personal pronoun) you had "su madre" (not a personal pronoun), then -Ella escribe a su madre would be correct, but less common -Ella le escribe a su madre would be the most common option. Unless you put su madre before the verb, because then: -*A su madre escribe ella, no Paquito is incorrect -A su madre le escribe ella, no Paquito is correct When, then, do you not use the pronombre personal átono together with the complement it refers to? With a direct object that comes after the verb: -Vio a su madre is correct -*La vio a su madre is incorrect ------- BTW, I don't think explicit knowledge of this bit of grammar is gonna help you, I'd just try getting an intuitive feel for it and not split hairs! Good luck with your Spanish :)

Maybe it'd be easier if you think about the "objeto directo (direct object)" and to know which it is in a sentence, is making the question "¿qué + verbo? or ¿a quién/quiénes + verbo?" Example. *(Juan) despidió a Pedro. Donde: verbo = despidió Objeto directo: ¿a quién despidió? A Pedro (a él). Yo: ¿a quién despidió? A mí. - ME despidió Tú: ¿a quién despidió? A ti. - TE despidió Él: ¿a quién despidió? A él. - LO despidió Ella: ¿a quién despidió? A ella. - LA despidió Ustedes: ¿a quién despidió? A ustedes. - LOS despidió Nosotros: ¿a quién despidió? A nosotros. - NOS despidió And in your example, "ella escribe a él" does not sound correct. Hope that helps! (:

Well there are two types of pronouns the direct object (me,te,lo,la,nos,os,los,las) and indirect object (me,te,le,nos,os,les). The direct object pronoun is the object that directly receives the action of the verb. It also answers the question what? or whom?. An example would be John hits the ball. Hits is the verb and ball is the direct object so, if you used a direct object pronoun for this sentence it would be John la golpea because, ball in Spanish is pelota which is singular feminine word so that's why you use la. Another example is I bought the flowers ( Yo las comprè). The reason you use Las is because flowers is a plural feminine word ( las flores). For indirect object pronouns you are trying to answer the question of To whom? or For whom?. An example would be He gives the book to Maria. Maria is the indirect object and the book is the direct object. This is how it is written Èl le da el libro a Maria. He gives who the book, Maria gets the book. The upside is most of the time if there is a indirect object then there will be a direct object as well. Yet, there are exceptions so, if you want to say "I told her". You would say "Le dije a ella" because, the word "it" is already assumed in the sentence. There are a few like these but it just takes practice. Hopefully I didn't confuse you even more and if you have anymore questions or want more examples I'll be glad to help.