fix typo

modules/variable-argument-functions.md

@@ -28,7 +28,7 @@ We already saw in [the numbers module](/modules/numbers.md) that you need to
 match the type of arguments with the type of conversion specifiers.  Why does
 the following work even when built in 32 bits?  We are using an argument of type
 `char`, which is 1 byte, but the `printf` functions assumes through the `%d`
-specifier there are 4 bytes on stack (x32) or in the register (x64).  Yes it
+specifier there are 4 bytes on stack (x32) or in the register (x64).  Yet it
 works.  Why?
 
 ```C