Peninsular Spanish

Processes of interaction and levelling between standard (a construct popularly perceived as based on northern dialects) and nonstandard varieties however involve ongoing adoption of conservative traits south and innovative ones north.

[7][8] According to folk tradition, the "purest" form of Peninsular Spanish is spoken in Valladolid, although the concept of "pure" languages has been rejected by modern linguists.

[13] In an area of northern Spain, centered on Burgos, La Rioja, Álava and Vizcaya and also including Guipúzcoa, Navarra, Cantabria and Palencia, the imperfect subjunctive forms tend to be replaced by conditional ones.

[15] In a chunk of northwestern Spain which includes Galicia and Bilbao and excludes Barcelona, Madrid, and Seville, the sequence /tl/ in words such as atleta 'athlete' and Atlántico 'Atlantic' is treated as an onset cluster, with both consonants being part of the same syllable.

Dialects in central and northern Spain and Latin American Spanish contain several differences, the most apparent being Distinción (distinction), i.e., the pronunciation of the letter z before all vowels, and of c before e and i, as a voiceless dental fricative /θ/, as in English th in thing.

A restricted form of distinción also occurs in the area around Cusco, Peru, where [θ] exists in words such as the numbers doce, 'twelve', and trece, 'thirteen'.

[18] Additionally, all Latin American dialects drop the familiar (that is, informal) vosotros verb forms for the second person plural, using ustedes in all contexts.

Words in bold are unique to Spain and not used in any other country (except for perhaps Equatorial Guinea which speaks a very closely related dialect, and to a lesser extent the Philippines).