Ojibwa is recent years has been written in the Nichols or Fiero orthography, where long vowels are written as double letters (aa, ii, oo), and some consonants are digraphs, where two letters make one sound (like sh as in ship and zh as in measure).  In the dialects using this orthography, there is little confusion or problem, so that “aa” is always long “a”.  However, in the western dialect, Saulteaux, it is possible for two short vowels to appear side by side, so that “aa” could be long “a”, or two instances of short “a”.  To solve this problem, Saulteaux people using Roman orthography write long vowels with an accent, often an acute (á).  Saulteaux is traditionally written in Syllabics, which similarly uses a dot accent to mark long vowels.

Digraphs present a similar problem, as in the English word “hothouse”.  According to English tradition, “th” is pronounced as one sound (phonetically /θ/).  Does this mean that "hothouse" is pronounced /hαθaws/?  Of course not, English speakers know that in this case, the “t” and “h” are spoken separately, but one would not be aware of this from the spelling.  If English used a unique letter for “th”, there would be no such confusion.