Are you talking about Welsh? If so that's a fairly silly objection. I'm not sure what your point is at all.
That "free movement of people" right the papers keep talking about? That we would need to keep if we wanted access to the single market? That means there are no barriers to EU migrants.
Almost 50% of the record 335,000[1] that migrated to the UK last year were from the EU, which has no barriers. Although I admit it clearly shows the UK government has no actual intention of stopping immigration if it's still letting 195,000 odd non-EU migrants in.
As a bit of a side note, I would thoroughly recommend reading Ayesha's Gift, a recent release, to get a glimpse into the world of immigrants in the UK, the racism they face, but also the consequences of not integrating them properly and how their culture can be entirely alien to ours. It's also an excellent true crime book.
[1] https://www.ons.gov.uk/peoplepopulationandcommunity/populati...