Surnames are often distinguished from ordinary nouns with the same pronunciation by having a final "e" or by doubling the final letter: Clarke/clerk, Trollope/trollop, Hogg/hog, Greene/green

Content words such as nouns usually have more than two letters; grammatical words such as pronouns and pre-positions have one or two: inn/in, bye/by, eye/I, two/to, ore/or, sew/so, know/noFairly common two-letter exceptions: go, ax (US), ox, hi, old spelling of musical notes (do, re, mi etc), printer's measurements (en, em), pi, id, ta

Some Scrabble players' exceptions: aa, ai, ba, bo, bu, jo, ka, ky, od, om, oo, qi, ri, xi, ut,

Content words with added consonant to avoid being function word: add, egg, odd, ebb

"th" corresponds to the voiced 'th' /D / in nouns such as third or Thetford, but to the voiceless 'th' /T /in grammatical words such as the and their: thistle/this, Thanet/than, Theydon Bois/they. Occasionally it is silent /ø/ as in 'often'.

initial 'th' in initial 'th' in medial/final 'th' others
function words content words
/D / /T / /D / or /T / /t/ or /ø/

they Theydon Bois bath /T / asthma /ø/

their theft whether /D / isthmus /ø/

them thimble breathe /D / Anthony /ø/

this thistle ether /T / Esther /t/

that thatch either /D /

‘silent’ final "e" is used:

— at the end of a word after a final VC sequence consisting of a ‘long’ vowel (spelled with a single letter) followed by a single consonant:late, mete, debate, tune, fine, bone

— after a final /s/, /z/ and /¶ / following ‘long’ vowel digraphs (combinations of two written vowel letters corresponding to a single speech sound), or ‘short’ vowel plus consonant; crease, house, maize; tense, cleanse

— after a stressed ending consisting of a ‘short’ vowel and a double consonant in words borrowed from French: brunette, cassette, rosette, giraffe

sources: mainly adapted from Carney