A lot of fifth graders are pretty smart people. I believe they can learn all of these words.
2-letter words
bo, do, go, ho, jo, lo, mo, no, so, to, wo
3-letter words
ado, ago, avo, azo, bio, duo, ego, fro, hao, mho, pro, rho, tao, tho, two, udo, upo, who
4-letter words
aero, agio, also, alto, ambo, ammo, arco, arvo, auto, brio, bubo, capo, cero, chao, ciao, dado, dato, deco, demo, dido, duro, echo, eddo, ergo, euro, expo, fado, fano, faro, fico, fido, filo, fino, giro, gyro, halo, hero, hypo, info, inro, into, jato, jiao, judo, kayo, keno, keto, kilo, kino, kudo, leno, levo, lido, limo, lino, mako, mano, mayo, memo, meno, milo, miso, pepo, peso, prao, rato, redo, repo, sago, sego, shmo, silo, sumo, sybo, taco, taro, thio, thro, tiro, trio, typo, tyro, umbo, unco, undo, unto, updo, veto, vino, wino, zero
5-letter words
abmho, aggro, Alamo, altho, amido, amigo, amino, audio, aviso, azido, banco, banjo, basso, beano, bilbo, bimbo, bingo, bravo, bucko, buffo, bunco, bunko, burro, buteo, cacao, cameo, campo, canso, canto, cargo, cello, cento, chiao, chico, chino, chiro, Cisco, claro, credo, curio, cusso, cyano, cyclo, danio, datto, dekko, diazo, dildo, dingo, dipso, disco, ditto, erugo, fillo, fugio, fungo, gecko, genro, gesso, gismo, gizmo, grego, guaco, guano, guiro, gumbo, gusto, hallo, helio, hello, hillo, hippo, hullo, hydro, imago, imido, imino, intro, jingo, jumbo, junco, junto, Kendo, kiddo, kusso, laevo, largo, lasso, lento, limbo, lingo, litho, llano, macho, macro, mambo, mango, matzo, metro, mezzo, micro, mimeo, misdo, mucro, mungo, nacho, narco, nitro, panto, pargo, paseo, patio, pedro, pengo, pesto, petto, piano, pingo, pinko, pinto, pisco, primo, punto, putto, radio, ratio, recto, repro, retro, rhino, salvo, sambo, schmo, scudo, secco, segno, servo, sexto, shako, sicko, sixmo, spado, steno, sulfo, tango, tanto, tardo, tempo, trigo, turbo, uredo, verso, video, vireo, vulgo, wacko, whamo, wilco
6-letter words
adagio, aerugo, aikido, akimbo, albedo, albino, alnico, ammino, anatto, aristo, arseno, arsino, ausubo, bagnio, barrio, bayamo, bistro, calico, casino, catalo, charro, cheapo, cheero, cicero, crambo, crypto, daimio, daimyo, dextro, dinero, duello, dynamo, embryo, enduro, enhalo, eringo, eryngo, escudo, fiasco, fresco, fugato, gabbro, galago, gaucho, gazabo, gazebo, gelato, gherao, ghetto, gingko, ginkgo, gitano, hairdo, hereto, hetero, indigo, jingko, kakapo, ladino, lanugo, latigo, latino, lavabo, legato, libido, macaco, maduro, manito, medico, merino, mikado, niello, nuncio, nympho, paramo, phyllo, picaro, presto, pseudo, psycho, pueblo, pumelo, quango, quarto, rabato, rancho, rebato, reecho, rialto, righto, rubato, rubigo, schizo, shacko, sleazo, smalto, speedo, spinto, stereo, stingo, stinko, stucco, studio, subito, tapalo, tenuto, teredo, tupelo, turaco, tuxedo, ultimo, vibrio, virago, weirdo, whacko, whammo, zydeco
7-letter words
agitato, allegro, animato, annatto, aparejo, arnatto, bacalao, bambino, beefalo, bracero, bravado, buffalo, burrito, bushido, cabildo, calando, calypso, carabao, cassino, cattalo, cavetto, cembalo, centavo, centimo, chamiso, cheerio, chicano, crusado, cruzado, curacao, eightvo, electro, embargo, esparto, farrago, gambado, gestapo, guanaco, hidalgo, impasto, inferno, lentigo, lumbago, maestro, magneto, marcato, marengo, marrano, memento, mendigo, mesteso, mestino, mestizo, mulatto, nelumbo, pachuco, paesano, paisano, palazzo, pampero, passado, picacho, pimento, pintado, pintano, placebo, primero, prurigo, relievo, reverso, rilievo, ripieno, saguaro, sahuaro, sapsago, scalado, scherzo, semipro, senecio, sentimo, serpigo, sfumato, stretto, subecho, subzero, supremo, synchro, tallyho, tamarao, tangelo, testudo, thereto, timpano, tympano, underdo, undergo, unmacho, vaquero, verismo, vertigo, vibrato, wendigo, whereto, windigo, zamarro, zapateo, zemstvo, zingano, zingaro
8-letter words
alfresco, amaretto, antihero, armigero, arpeggio, atamasco, barbasco, bargello, barranco, buckayro, cabestro, cabresto, camisado, castrato, caudillo, cavalero, chechako, chubasco, cicisbeo, cilantro, classico, cruzeiro, curculio, duecento, espresso, expresso, falsetto, fandango, fellatio, flamenco, flamingo, fricando, garbanzo, gazpacho, graffito, guacharo, hereinto, hereunto, hitherto, huaracho, impetigo, innuendo, intaglio, jalapeno, largando, leggiero, lentando, libeccio, libretto, machismo, martello, mercapto, milesimo, millimho, muchacho, mundungo, neutrino, pachinko, palmetto, parlando, perfecto, pimiento, plumbago, presidio, prunello, ranchero, renegado, sargasso, scenario, seicento, seraglio, spiccato, staccato, stiletto, superego, superpro, tapadero, terrazzo, trapunto, trecento, twelvemo, vitiligo, zecchino
9-letter words
altiplano, andantino, antimacho, antipasto, armadillo, barricado, bastinado, burladero, caballero, campesino, capriccio, carbamino, carpaccio, centesimo, cheechako, cigarillo, crescendo, desperado, glissando, hacendado, larghetto, lazaretto, libecchio, magnifico, manifesto, mustachio, paparazzo, pasticcio, pistachio, pizzicato, punctilio, quebracho, radicchio, sanbenito, semimicro, sgraffito, simpatico, sixteenmo, strappado, superhero, tamarillo, thereinto, thereunto, thitherto, whereinto, whereunto, zapateado, zucchetto
10-letter words
allargando, allegretto, baldachino, camerlengo, cappuccino, carabinero, diminuendo, fantastico, fianchetto, haciendado, impresario, intermezzo, latifundio, lentissimo, maraschino, parmigiano, peccadillo, pianissimo, preembargo, recitativo, ritardando, saltarello, scherzando, stringendo, supercargo, superjumbo, supermacho, supermicro, ultramicro
11-letter words
accelerando, archipelago, caudillismo, cinquecento, decrescendo, embarcadero, internuncio, prestissimo, punchinello, rallentando
12-letter words
antineutrino, banderillero, divertimento
13-letter words
generalissimo
678 words found.
Some words that end in O are:agoalsobanjobravadobravocockatoocombocommandocuriododumbodynamoechoergoflamingogizmogogoohalohelloheroigloointokangarookazookiddokilokimonolassoloomemonoontopatiopeekaboopianopotatoradiorhinorodeososolotattoototomatotootornadotorsotriotwountovetovideovirtuosowhowooyahooyo-yozerozoo
Some six letter words that have O being the 5th letter:ActionAnalogAnchorAnyhowAuthorBaboonBallotBambooBarhopBarrowBeaconBeckonBellowBestowBetookBettorBillowBishopBorrowBottomBunionBusboyButtonCannonCannotCanyonCaptorCarbonCarboyCarhopCarrotCartonCensorClamorCocoonCommonConvoyCottonCouponCowboyCrayonCuckooCursorCustomDeaconDebtorDeployDoctorDollopDragonEditorEggnogEmployEscrowFactorFalconFallowFathomFellowFervorFlavorFollowForgotFusionGallonGallopGambolGlamorGodsonHallowHansomHarborHereofHereonHollowHorrorIceboxIndoorInflowJargon
Some Scrabble words that end with O are:banjocockatoocombocommandocuriododominodumbodynamoechogizmogogoohalohelloherokangarookazookiddokilokimonomemonopatiopeekaboopotatoradiorodeosotattoototomatotootornadotorsotriovetovideovirtuosowhowooyahoozerozoo
Some words ending in the vowel O are:bongobravohalohelloherojellopianopolopotatoshampoosilosolotattootomatoweirdozero
Oleo, olio, onto, ordo, orzo and ouzo are 4 letter words that begin with the letter o and end with o.
Igloo, incognito, indigo, inferno, info, into and intro are words. They begin with I and end with o.
False. Feminine words end in "a" while masculine words end in an "o"
Some six letter words with O as the fifth letter are:baboonballotdialogdiatomfathomflavorglycolhobnobhotrodlapdogmatzohpeapodperiodphenompistolpogrompompomrandomransomsalmonsaloonschoolseldomtiptoetripod
Some five letter words that have a third letter O and fifth letter E are:abodeaboveadobeadorealonearoseatoneawokebiomeblokeboozebrokechokechorechoseclonecloseclovecronediodedronedroveelopeemoteerodeevokefrozegeodeglobeglovegnomegoosegropegrovekroneloosemoosenooseozonephoneprobeproneproseprovequotesconescopescoreshoneshoreshoveslopesmokesnorespokesporestokestolestonestorestovesworetholethosetrovewholewhosewrote
Some words that end in VO are:bravoparvooctavosalvo
no, so, to, too,
agoallegroalsoaltoarmadilloaudio