uvular R

From: João S. Lopes Filho
Message: 7722
Date: 2001-06-22

In Portuguese there's also an uvular R (the Portuguese grammar I have calls it multiple dorso-uvular vibrant, or multiple velar vibrant). This R is:
 the R in beginning of word cf. rato (rat), Ronaldo (the soccer player)
the digraph RR - cf. carro (car), arroz (rice)
 
ther R in ending of syllabe or before consonant cf. porta (door), amor (love) - this pronnounce is not common in all parts of Brazil, it's usual in Rio de Janeiro and some regions in Northern and Northeastern Brazil.
In Rio de Janeiro this uvular R is pronnounced almost like English H or Spanish J. So, in Rio, we pronnounce "Rio" almost like "Hill".
In Southern Brazil the R before consonants and word-ending is pronnounce like dental R. In some regions of Southern Brazil, even the RR is pronnounced like dental R. In regions of Southeastern hinterland the R is retroflex (Tupian influence?).
 
Is it true that Puertorican Spanish has an uvular R due influence of Portuguese?