Selective English? A common affliction, especially among illegal aliens.
We had a mojidora with selective English whose dog used to roam and threaten everyone. I went to her house to tell her the dog was loose and that if she didn't come and get it that I'd have to call Animal Control. She stood there, smiling, and said, over and over again, "No English."
I told her she must have been a very successful prostitute in her homeland because all of her children so obviously had different fathers and her husband must have been her pimp. English came out, admittedly first in very short Anglo-Saxon and Norman French form, but she got her dog although she did try to hit me first. Fortunately for us, her husband was arrested on a felony and the rest of the family chose to leave the area voluntarily when he went to prison. I think the fact that her teenage son was assisting his father in the family enterprises might have had a bearing since he was released from the youth center and they were gone within the month. They're probably over in the Central Valley dealing their drugs and committing auto burglaries instead of doing it on my block.