I'm not aware that beef and deaf have a plural form, actually. Without a good rule to fall back on, use the dictionary. It will list the plural form if it is anything other than just adding an S.
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Anonymous... must be a vowel before the "f" in order for the plural to end in -ves. For instance, elf=elves, wolf=wolves, scarf=scarves, staff=stavesThree out of four of your examples do not have a vowel before the "