Here’s another one for you:
Right before Az Yashir we have the passuk (Shmos 14:31):
???????? ?????????? ???-?????? ??????????, ?????? ?????? ?????? ????????????, ??????????? ?????, ???-??????; ?????????????, ????????, ??????????, ????????
Note the two yuds in the word ???????????. That makes the sh’va under the reish into a sh’va na. Thus the word should be pronounced Vayir’u (as opposed to Vayiru).
It changes the meaning of the word. The word, as written means “and they feared” (or, perhaps “were awed”). If you pronounce it as Vayiru (with a sh’va nach) it become “and they saw” as in the following passuk later in the same parsha (Shmos 16:15):
?????????? ?????-??????????, ??????????? ????? ???-?????? ??? ????–???? ??? ???????, ???-????; ????????? ??????, ???????, ???? ????????, ?????? ????? ?????? ????? ?????????.
Note that here, the word “Vayiru” has only a single yud. That makes the Sh’va under the resh into a sh’va nach. Here the word means “and they saw.”
The Wolf