Drowning in translation

I was wondering if anyone else was sort of thrown off by the Spanglish used in "Drown"? I've read his other book "The Brief Wondrous Life of Oscar Wao" which does the same thing as far as throwing random Spanish words in with English sentences and I was curious about it then as well. I am a Spanish major so I know what most of the words mean so it isn't a matter of not knowing what he's saying, in most cases, but it just seems to throw off the flow of reading the sentence to me. Also, I don't understand how he chose which words to use the Spanish of. Some I understand, like tio (uncle) and other family names...but then random words like barrio (neighborhood) and campo I don't understand why those words were chosen. I understand that a lot of Latin-Americans do use Spanish words in their regular conversations and doing so in his writing, I think, makes Diaz' characters seem more real but I'm curious about what you guys think about it. Is it helping or hindering your reading? Are you looking up what some of the words mean or just skimming over them and implying meaning from the rest of the sentence? Have you noticed any patterns among the words that Diaz chose to put in Spanish?