People are easily trained for most work. There are plenty of people who speak Spanish. Most jobs need basic on the job training.
Immigrants have always worked harder than the locals. This includes the countries where the immigrants come from. The Irish used to kid about who has been left behind standing in a field all day long doing nothing.
The Chinese workers are not good at all in the US. I have first hand experience with a Chinese restaurant in my college days. Chinese immigrant workers got a bus up to the restaurant. Most of them the next day were fired as lazy and shipped back down to NYC. In China town NYC there are plenty of sales booths in building lobbies where people sit all day doing next to nothing, occasionally selling something. The idea that Chinese labor is hardworking is bigotry. It is not generally true.
Latino labor has been so great that Latinos in the US as a GDP would be ranked 5th in the world for wealth. That is hard work.