Scandinavia's earliest farmers exchanged terminology with Indo-Europeans. 5,000 years ago, the Yamnaya culture migrated into Europe from the Caspian steppe. In addition to innovations such as the wagon and dairy production, they brought a new language -- Indo-European -- that replaced most local languages the following millennia. But local cultures also influenced the new language, particularly in southern Scandinavia, where Neolithic farmers made lasting contributions to Indo-European vocabulary before their own language went extinct, new research shows. Source 1u.
Now this is fascinating and something I haven't studied before. I learned something new and cool today. So, apparently this Yamnaya culture contributes about half the DNA to northern Europeans and about a third to southern Europeans, as well as much of our linguistic attributes. This is why it is easier for English speakers to learn German, French, Spanish. Italian, or Greek than it is to learn Chinese or Arabic. The indo European languages have a common ancestry.