1 syllable:
'gain, behn, behne, ben, benn, benne, bren, brenn, brenne, chen, chien, dehn, dehne, den, denn, denne, drehen, en, fehn, fen, fenn, gen, gen-x, glen, glenn, gren, gwen, gwenn, hehn, hen, henn, henne, hren, jen, jenn, jenne, kehn, kehne, ken, kenn, kenne, kren, krenn, lehn, lehne, len, men, menn, menne, mesne, n, n., pen, penh, penn, penne, phen, prehn, prenn, rehn, ren, renn, renne, schwenn, sen, senn, senne, shen, splen, splen-, sten, sven, sweyn, ten, tenn, tenne, thegn, then, tien, venn, venne, wen, when, wren, wrenn, yen, yene, zen

2 syllables:
(paren, )paren, achtzehn, adren, advene, again, aiden, aidenn, airmen, almen, alpen, amen, and then, antenne, askmen, aufsehen, aussehen, bagmen, ballpen, beaubien, beauchesne, behen, bienne, big ben, brienne, brood hen, bruntjen, bullpen, but then, cayenne, chang chen, chienne, chretien, chris fehn, conmen, courchesne, cow pen, culmen, delenn, demesne, derouen, drakkhen, dreizehn, duchenne, duchesne, dufresne, eghen, elsewhen, eugen, fat hen, fengtien, fernsehen, filmen, flagmen, fulmen, gatemen, gerzean, grayhen, gray hen, greyhen, guienne, gunmen, guyenne, heath hen, holpen, hotien, house wren, ilmen, impen, inguen, jiawen, john glenn, kal penn, kroatien, landmen, larchen, lawmen, legmen, light pen, longden, lumpen, lunen, luxgen, magten, mahen, mailmen, maintien, marchen, maren, marsh hen, marsh wren, mayenne, mehen, meighen, ming-jen, moor-hen, moorhen, mud hen, neunzehn, nexgen, nguyen, northglenn, oilmen, panchen, paren, penmen, perenne, phen-fen, phenfen, phnom penh, pitchmen, playpen, pnom-penh, po-jen, protien, qichen, quill pen, rechen, reten, reynmen, rock wren, sage hen, saint-ouen, salmen, sandmen, sayen, schoolmen, scott glenn, sea pen, sechzehn, sedge wren, sheep pen, sheng-fen, sheng-yen, shenzhen, sheyenne, siebzehn, somewhen, soutien, spanien, sparen, steve chen, strawmen, swagmen, take ten, tegmen, teng-wen, transenne, turkmen, u. n., umgehen, unten, upenn, uren, urgen, versehen, vienne, vierzehn, vorgehen, wheelmen, wise men, wood hen, woolmen, wuzhen, xue chen, yuen, zak penn

3 syllables:
(left-paren, )close-paren, )end-paren, )right-paren, abdrehen, adrienne, afscn, almaden, anchormen, angehen, angesehen, antwerpen, anywhen, arfcn, arienne, aufstehen, b.j. penn, ballpoint pen, biel/bienne, biogen, bisdn, bonchretien, born-again, broody hen, businessmen, c. n. n., cactus wren, cattle pen, choukoutien, chou tien-chen, clergymen, cnn, codepen, colormen, councilmen, countermen, cryogen, dandy-hen, darlehen, draisienne, duramen, dylan penn, dynapen, eintreten, emu-wren, energen, entretien, euroyen, fabienne, fill again, five-and-ten, fountain pen, fudepen, gebrochen, georgien, georgienne, geschehen, guinea-hen, guinea hen, hambleden, handymen, haslingden, haute-vienne, henequen, iain glen, indienne, innichen, iogen, ironmen, itelmen, jenny wren, jianzhen, julianne, julienne, jungle hen, kelaguen, kungsholmen, legumen, lesbienne, lingayen, lpn, m. f. n., madeleine, maori hen, marine le pen, metalmen, michael penn, middlemen, miniten, minutemen, mirabehn, molimen, motormen, mussulmen, nathan chen, neupogen, now and then, once again, only when, patrolmen, persienne, powergen, pushed again, repairmen, sagapen, saracen, sdn, sebastien, setting hen, signalmen, synergen, tappit-hen, tavernmen, then again, thereagain, tibicen, tienanmen, uniden, vannguyen, verstehen, waterhen, water hen, weathermen, winter wren

4 syllables:
)end-the-paren, 18 again, b-isdn, bjaodn, boumedienne, canadien, canadienne, comedienne, cracovienne, e. s. p. n., environment', equestrienne, erythrophleine, gambling den, immunogen, kalifornien, kimiko glenn, knin, mazedonien, melanogen, msisdn, n-isdn, never again, new zealand wren, now and again, obesogen, opium den, organogen, over again, parisien, parisienne, pepsinogen, rock cornish hen, sebastiane, see you again, sherilyn fenn, sicilienne, thieboudienne, tiananmen, time and again, toshimaen, tragedienne, tyrolienne, valencienne, valravn, varsovienne, vlaanderen

5 syllables:
again and again, asean, auseinandergehen, carolina wren, cnnfn, euro-isdn, expressvpn, kemono jihen, kobenhavn, mother carey's hen, nflpn, nordvpn, opencpn, openvpn, protonvpn, purevpn, stdin, time and time again, valerie constien, victor osimhen

6 syllables:
anna van bellinghen, bootstrapcdn, cap-de-la-madeleine, every now and then, paracyanogen, sulphocyanogen, thiocyanogen

7 syllables:
johnny english strikes again, never say never again, over and over again, persulphocyanogen, perthiocyanogen, youngboy never broke again