Guanche is an extinct language that was spoken by the Guanches of the Canary Islands until the 16th or 17th century. It died out after the conquest of the Canary Islands as the Guanche ethnic group was assimilated into the dominant Spanish culture. The Guanche language is known today through sentences and individual words that were recorded by early geographers, as well as through several place-names and some Guanche words that were retained in the Canary Islanders' Spanish.

Guanche has not been classified with any certainty. Many linguists propose that Guanche was likely a Berber language, or at least genealogically related to the Berber languages to some extent as an Afroasiatic language.^[2][3][4][5] However, recognizable Berber words are primarily agricultural or livestock vocabulary, whereas no Berber grammatical inflections have been identified, and there is a large stock of vocabulary that does not bear any resemblance to Berber whatsoever. It may be that Guanche had a stratum of Berber vocabulary but was otherwise unrelated to Berber.^[1] Other strong similarities to the Berber languages are reflected in their counting system, while some authors suggest the Canarian branch would be a sister branch to the surviving continental Berber languages, splitting off during the early development of the language family and before the terminus post quem for the origin of Proto-Berber.^[5]

The name Guanche originally referred to a "man from Tenerife",^[6] and only later did it come to refer to all native inhabitants of the Canary Islands. Different dialects of the language were spoken across the archipelago. Archaeological finds on the Canaries include both Libyco-Berber and Punic inscriptions in rock carvings, although early accounts stated the Guanches themselves did not possess a system of writing.

The first reliable account of the Guanche language was provided by the Genovese explorer Nicoloso da Recco in 1341, with a list of the numbers 1–19, possibly from Fuerteventura. Recco's account reveals a base-10 counting system with strong similarities to Berber numbers.

Silbo, originally a whistled form of Guanche speech used for communicating over long distances, was used on La Gomera, El Hierro, Tenerife, and Gran Canaria. As the Guanche language became extinct, a Spanish version of Silbo was adopted by some inhabitants of the Canary Islands.

Guanche numerals are attested from several sources, not always in good agreement (Barrios 1997). Some of the discrepancies may be due to copy errors, some to gender distinctions, and others to Arabic borrowings in later elicitations. Recco's early 1341 record notably uses Italian-influenced spelling.

* Also nait,' an apparent copy error. Similarly with alda-morana for expected *alda-marava.

Later attestations of 11–19 were formed by linking the digit and ten with -ir: benirmarago, linirmarago, etc. 20–90 were similar, but contracted: linago, amiago, etc. 100 was maraguin, apparently 10 with the Berber plural -en. Recco only recorded 1–16; the combining forms for 11–16, which did not have this -ir-, are included as the hyphenated forms in the table above.

Spanish does not distinguish [b] and [v], so been is consistent with *veen. The Berber feminine ends in -t, as in Shilha 1: yan (m), yat (f); 2: sin (m), snat (f), and this may explain discrepancies such as been and vait for 'one'.

Cairasco is a misparsed counting song, besmia mat acosomuset tamobenir marago. Ses '6' may have got lost in the middle of somuset ( ← *somussesset).

Starting with Cedeño, new roots for '2' and '9' appear ('9' perhaps the old root for '4'), new roots for '4' and '5' (arba, kansa) appear to be Arabic borrowings, and old '5', '6', '7' offset to '6', '7', '8'.

Below are selected Guanche vocabulary items from a 16th-century list by Alonso de Espinosa, as edited and translated by Clements Robert Markham (1907):^{[7]: xx–xxiv}

Below are some additional basic vocabulary words in various Guanche dialects, from Wölfel (1965):^[9]