The sound /ə/ is usually written with the letters ‘a’ (again, woman), ‘o’ (today, police), ‘e’ (open, quiet), ‘er' (water, mother).

Some words have the sound lal when they are weakly stressed in a sentence, and are written with 'a’ (am, a, an, and, as, at, shall), ‘o’ (for. fron:
of, to) and ‘e’ (the, them).