Well, that's a question of Japanese phonetics. Basically, just know that the letters we use for Japanese words don't really equal the Japanese sounds for those letters as we use them. That is, the "h" in ひ sounds a lot like "sh" to us native English speakers, so it isn't really "h" in that instance. I hope this doesn't confuse or scare you (or both). Just listen and do your best to imitate the native speakers. That's the best advice I can give you. :sorry: