The native name for Dutch in both Belgium and the Netherlands is Nederlands. In Flanders, the term Vlaams may also be used to describe Standard Dutch, while Hollands may be used colloquially to refer to the standard language in parts of the Netherlands. In English, the language of the Netherlands and Flanders is referred to as Dutch, which comes from Proto-Germanic *þiudiskaz meaning "of the people". During the Early Middle Ages, the term Theodiscus was used in reference to the Germanic vernaculars as opposed to Latin, the language of the Catholic Church. In northwestern West Francia, the term "Dutch" came to mean the opposite of the Romance-speaking population. During the High Middle Ages, "Dutch" referred specifically to the Germanic dialects spoken in the Low Countries. The endonym Nederlands replaced the older endonym Dietsch or Duytsch in the Low Countries, and Nederduytsch received competition from Nederlands in the 16th century, with Nederlands ultimately becoming the most common designation by the close of the 18th century. Nederduits and Hoogduits were later used as Dutch exonyms for Low and High German dialects, respectively. In the 19th century, "Diets" was revived by Dutch linguists and historians as a poetic name for Middle Dutch and its literature.
Old Dutch, like Old English (Anglo-Saxon), Old High German, Old Frisian, and Old Saxon, developed around the same time period. The language was initially a set of Franconian dialects spoken by the Salian Franks in the 5th century and evolved over 15 centuries into Middle Dutch and then Modern Dutch. During this evolution, Dutch pushed Old Frisian from the western coast to the north of the Low Countries and replaced Old Saxon in the east, but Dutch was replaced in neighboring regions in France and Germany. The transition between Old, Middle and Modern Dutch was gradual, with the emergence of the Dutch standard language being one of the few moments of noticeable change. The sentence in Old, Middle and Modern Dutch and English is an example of the development of the Dutch language.
Dutch dialects are different variations of the Dutch language spoken within the same geographic area as the standard Dutch language. Although they are influenced by the standard language, some of these dialects are distinct and are found in the Netherlands and in Belgium's Brussels and Flemish regions. The areas in which these dialects are spoken often correspond to former medieval counties and duchies. In the Netherlands, there is a distinction made between a dialect and a "regional language," while in Belgium this distinction is not made. However, the use of dialects and regional languages is declining, especially in the Netherlands. Research shows that the percentage of the Dutch adult population that speaks a dialect or regional language on a regular basis has dropped from 27% in 1995 to just 11% in 2011. The decline is even more pronounced among children, with the percentage of children who speak a dialect or regional language dropping from 12% in 1995 to just 4% in 2011. Dialects are more commonly spoken in rural areas, but some cities also have a distinct city dialect. Dialects used to extend across the borders of other standard language areas, but the influence of the standard language has broken this continuity in most cases.
The majority of Dutch vocabulary is of Germanic origin, with about 20% being loanwords. The main source of foreign influence on Dutch vocabulary is French and related languages, accounting for over a third of all loanwords. Latin, which was widely used in the southern Low Countries, is the next largest contributor with 6.1% of loanwords. The impact of High German and Low German, which were influential until the mid-20th century, is 2.7%. However, many of these loanwords have been "Dutchified". Dutch has been borrowing words from English since the mid-19th century, due to the increasing power and influence of Britain and the United States. English loanwords now make up 1.5% of the Dutch language, but continue to increase. Conversely, Dutch has contributed loanwords to English, accounting for 1.3% of its lexicon. The main Dutch dictionary is the Van Dale groot woordenboek der Nederlandse taal, which contains around 268,826 headwords. The widely used 45,000-page Woordenboek der Nederlandsche Taal, a scholarly work that took 147 years to complete, contains all recorded Dutch words from the Early Middle Ages onward.