a (an)——without, not amphi——both, around ana——up, back, through anti——against, opposite apo (ap)——from cata——down
dia——through en (em)——in epi (ep)——upon hyper——over, excessive hypo——under meta (met)——beyond, change syn (sy, syl, sym)——with, together
In Greek words also we will find _ph_ with the sound of _f_. We know that _symmetrical, hypophosphite, metaphysics, emphasis,_ etc., are Greek because of the key we find in the prefix, and we are thus prepared for the _y_'s and _ph_'s. _F_ does not exist in the Greek alphabet (except as ph) and so we shall never find it in words derived from the Greek.
The English prefixes are not so often useful in determining peculiar spelling, but for completeness we give them here:
a——at, in, on (ahead) be——to make, by (benumb) en (em)——in, on, to make (encircle, empower) for——not, from (forbear) fore——before (forewarn) mis——wrong, wrongly (misstate) out——beyond (outbreak) over——above (overruling) to——the, this (to-night) un——not, opposite act (unable, undeceive) under——beneath (undermine) with——against, from (withstand)
There are a few rules and applications of the principles of word-formation which may be found fully treated in the chapter on “Orthography” at the beginning of the dictionary, but which we present here very briefly, together with a summary of principles already discussed.
Rule 1. _F, l,_ and _s_ at the end of a monosyllable after a single vowel are commonly doubled. The exceptions are the cases in which _s_ forms the plural or possessive case of a noun, or third person singular of the verb, and the following words: _clef, if, of, pal, sol, as, gas, has, was, yes, gris, his, is, thus, us. L_ is not doubled at the end of words of more than one syllable, as _parallel, willful,_ etc.
Rule 2. No other consonants thus situated are doubled. Exceptions: _ebb, add, odd, egg, inn, bunn, err, burr, purr, butt, fizz, fuzz, buzz,_ and a few very uncommon words, for which see the chapter in the dictionary above referred to.
Rule 3. A consonant standing at the end of a word immediately after a diphthong or double vowel is never doubled. The word _guess_ is only an apparent exception, since _u_ does not form a combination with _e_ but merely makes the _g_ hard.