Linguistic controversy surrounds the people whose burial sites have been found, whether they spoke an Indo-European language or not, and even whether a change of pottery type or burying technique indicate a migration of people or merely the adoption of ideas.
Less controversial innovative features that distinguish the 'Battle-axe culture' from the earlier 'Beaker culture' that it infiltrated or simply superseded are the practice of burying the dead singly (instead of in megalithic group burials) under round tumuli enclosing a wooden mortuary house (a widespread practice), with grave goods.
For the first time in Europe, the bones of a domesticated horse are found in connection with the sites: the Tarpan, a forest pony that was native to Europe, but has been extinct since 1876. It is possible that wheeled carts were used in the corded ware culture.
However, a people must have existed in Jutland and the near areas before the Indo-Europeans arrived. The Germanic languages have a large number of non-Indo-European roots (especially sea terms; the first Indo-European speakers lived in an inland area). The only way to account for their existence is a language spoken in the area. Logically, a living language must have speakers.
The chief controversy centers on whether the Battle-axe people were the ones who supplied the non-Indo-European root-words in Germanic languages. These are a group of words that are common to the Germanic tongues, but which are not found in other Indo-European tongues, or whose root words are unlike the words of other kinds of Indo-European speech. These words are often found in the fields that have to do with ships, decks, keels, oars, and masts; another group of these words have to do with war, swords, helmets, and shields. Other such words are quite homely, like wife, house, bite, and chew. A few of these words are shared with the Celtic tongues. Most of these words are shared by all the Germanic tongues; few are found elsewhere, and the ones for which Indo-European roots have been put forth by the learned are quite unlike their word-kin in shape; there is great wrath among the wise about the beginnings of these words.