I'm defining our culture as being significantly based on pre Victorian to 1960, a time of insignificant immigration compared to the current situation of millions.I believe you've been trying to argue that immigration hasn't had any impact on our culture, but admit that the English language is based on imported languages from Europe, therefore immigration must have had an impact on our culture.
If you want to point to the cultural influence of Brok the Viking and how he always used to slur his r's when pronouncing place names, then feel free. Your point is still irrelevant.