Spanish Stressed and Unstressed Personal Object Pronouns

Spanish has two sets of personal object pronouns. They are stressed and unstressed. This distinction is connected to sentence stress. Though both words are stressed in isolation, the one which occurs at the end of the sentence is stressed. 

In English the object pronoun me occurs in the sentences My brother helped me and The present is for me. The position of the object pronoun is the same in English. It occurs at the end of the sentence.

However, in Spanish the sentences are Mi hermano me ayudó and El regalo es para mí. The words me and mí both mean me. The difference is that the first one is unstressed and the second is stressed. The unstressed pronoun occurs before the main verb and the stressed pronoun after the preposition.

Here are further examples of stressed and unstressed pronouns in Spanish:

Mi hermana te conoció. (My sister met you)

La pregunta es para ti. (The question is for you)

Mi primo la conoce. (My cousin knows her)

Su hermana va con ella. (Her brother is going with her)

Mi amigo lo conoce. (My friend knows him)

Su hermana está con él. (His sister is with him)

La película nos impresionó. (The movie impressed us)

Mis amigos están con nosotros. (My friends are with us)

Mis amigos los hicieron. (My friends made them)

La fiesta es para ellos. (The party is for them)

The stressed object pronouns ella, él, nosotros and ellos are also subject pronouns. Unlike English, Spanish has two sets of personal object pronouns. They occur in different positions in the sentence.