[5] According to Somersal, the English name for the people and language is derived from the Spanish word guapo, meaning "handsome" or "brave".

Jesse O. Sawyer published English-Wappo Vocabulary in 1965 and continued to study Wappo grammar throughout his life.

Other linguists who have contributed to the study of Wappo include William E. Elmendorf, Alice Shepherd, Sandra Thompson, Joseph Sung-Yul Park, and Charles N.

[11] The transcription style (bolded symbols below) is based on Sawyer's work with Somersal, with further interpretation by Thompson, Park and Li.

Thompson et al. propose that Wappo has three types of stops: plain, aspirated and glottalized.

paʔeat-ta-PST-lahkhiʔ-NEGpaʔ -ta -lahkhiʔeat -PST -NEG"did not eat"ah1SG:NOMte3SGoyaʔpotkeʔbreak--tisCAUS--taPST--lahkhiʔNEGah te oyaʔ keʔ - tis - ta - lahkhiʔ1SG:NOM 3SG pot break - CAUS - PST - NEG"I didn’t make him/her break the pot"Prefixes are also added to verb phrases.

ceDEMewfishceDEMk'ewman--iNOMt'umbuy--taʔPSTce ew ce k'ew - i t'um - taʔDEM fish DEM man - NOM buy - PST"that fish, the man bought (it)"Wappo allows for more freedom in word order in complement clauses, especially when they have first person subjects.

ah1SG:NOMceDEMk'ewmanewfishṭ'ohcatch--taʔPSThaṭisknow--khiʔSTATah ce k'ew ew ṭ'oh - taʔ haṭis - khiʔ1SG:NOM DEM man fish catch - PST know - STATah1SG:NOMhaṭisknow--khiʔSTATceDEMk'ewmanewfishṭ'ohcatch--taʔPSTah haṭis - khiʔ ce k'ew ew ṭ'oh - taʔ1SG:NOM know - STAT DEM man fish catch - PSTceDEMk'ewmanewfishṭ'ohcatch--taʔPSTah1SG:NOMhaṭisknow--khiʔSTATce k'ew ew ṭ'oh - taʔ ah haṭis - khiʔDEM man fish catch - PST 1SG:NOM know - STATIn noun phrases, demonstrative and genitive modifiers precede the noun, while numerals and adjectives follow the noun.

heDEMtončicathe tončiDEM cat"this cat"te3SG--meʔGENč'ešmabedte - meʔ č'ešma3SG - GEN bed"his/her bed"hintadayhopokathreeah1SG:NOMk'ešudeermehlahihunt--khiʔSTAThinta hopoka ah k'ešu mehlahi - khiʔday three 1SG:NOM deer hunt - STAT"for three days, I was hunting"In verb phrases, oblique arguments and adverbs come before the verb.

cephi3SG:NOMkuči:yaknife--thiʔINSTchicabearṭ'ohkill--taʔPSTcephi kuči:ya - thiʔ chica ṭ'oh - taʔ3SG:NOM knife - INST bear kill - PST"s/he killed the bear with a knife"The comitative case is marked with -k'a and is used to indicate accompaniment.

ah1SG:NOMmi2SG-k'a-COMčo:go-siʔ-FUTah mi -k'a čo: -siʔ1SG:NOM 2SG -COM go -FUT"I’ll go with you"The genitive case is marked with -meʔ.

i1SG--meʔGENlučtobacco--iNOMlakhiʔmissingi - meʔ luč - i lakhiʔ1SG - GEN tobacco - NOM missing"I don’t have any cigarettes"Wappo also has a locative case, which is marked with suffixes such as -pi "away from" and -cawoh "on top of".

thalwhat-i-NOMčhuyahouse-cawoh-on:topte-DIR-cewtefall-khiʔ-STATthal -i čhuya -cawoh te- cewte -khiʔwhat -NOM house -on:top DIR- fall -STAT"what fell on the roof?"

lučetobacconeʔhave--khiʔSTAThiʔQmiʔ2SG:NOMluče neʔ - khiʔ hiʔ miʔtobacco have - STAT Q 2SG:NOM"do you have any cigarettes?

"thalwhat-i-NOMčhuyahouse-cawote--on:top-DIR-cewtefall-khiʔ-STATthal -i čhuya -cawote- cewte -khiʔwhat -NOM house -on:top-DIR- fall -STAT"what fell on the roof?

Thompson et al. cite the sentences below as examples of an expanded use of the benefactive case that could have arisen from contact with English.

kaphecoffee--maBENEFah1SG:NOMmeywaterk'oboil--taʔPSTkaphe - ma ah mey k'o - taʔcoffee - BENEF 1SG:NOM water boil - PST"I boiled water for coffee"[heDEMtakaʔbasket-i]-NOMi1SG-ma-BENEFeniyaveryc'itihard-khi?-STAT[čočweave-ukh]-INF[he takaʔ -i] i -ma eniya c'iti -khi?

"In another potential example of English influence, the word neʔ-khiʔ "have" is used in deontic expressions, and its meaning is adapted as "have to".

ah1SG:NOMčohgo-ukh-INFneʔhave-khiʔ-STATmaʔajustheʔnowah čoh -ukh neʔ -khiʔ maʔa heʔ1SG:NOM go -INF have -STAT just now"I have to go right now"[6]Wappo had 5 varieties: BENEF:benefactive case DIR:directional prefixes