A girl sent me a coded word: 'pfaieg', I fail to decypher it

I'm absolutely no code master, nor novice. But it looks like a simple substitution code (is it even called this way?). NOTE: I'm Italian, and my English analysis could be wrong or misdirected.

Before opening it on my pc for a further analysis, let's say that the message is in English.

It begins with a single, capitalized letter: V. The easiest and most likely interpretation is that it is a I (capital i). Other less likely possibilities are A, O, and U, where O and U are far-fetched.

On to the next word: sbyybjrq. I can't find English words where double letters are immediately preceded and followed by a consonant, so I'd say Y is a consonant and B a vowel. We can probably solve the code just by trial and error with the V letter at the beginning of the message, but I like those kinds of mental exercises.

The other two words, gur and ehyrf, don't happen to bear any peculiarity.

/r/codes Thread