I am not sure about the laws, but I do remember my grandfather telling me about be beaten by British soldiers in the west of Ireland if they spoke in Gaelic (or "my tongue" as he called it), wore any outward symbol of of Irish "Pride" or symbol of nationhood (ie green, any pins from organizations deemed anti-british) etc. Eventually, he and most of his siblings fled to America to be free of the oppression in and around 1916-17.

So it may not be actual laws, but enforced "laws" by the ruling power.