There's more than a "smattering" of Hebrew in the English I use with my grandchildren, but they are learning more English than they would be if I didn't use any.
"Throw it in the pach, (garbage.)"
"Go to the toilet to make peepee."
There are terms they understand and even repeat like:
"Wash up." (Which they hear as one word, washup.)
English isn't a "foreign language" for them; it's familiar.
When I was babysitting, before we got the baby, toddler age but not yet independently walking, the mother of the elder's best friend called:
"M- said that you're giving them an English Lesson today. What time should I bring her?"
"Really, I didn't know that, but no problem, I'll put something together."
Within a few minutes, the "class of three little girls" were ready for their lesson. Obviously, I had no time to prepare "materials." When I was the temporary girls gym teacher, for 13 years, I used to start lessons with the song, "Head, shoulders, knees and toes," so I taught them that, which has a lot of vocabulary. Not even my granddaughters know all the words, so they put them at a more even starting level. We sang it a few times until the girls felt confident joining in. Then I "quizzed them" a bit.
Next part of the lesson was colors. They were all wearing some pink. I taught them the word and had them go around the room pointing the pink things and shouting "pink." Then we did it for white and blue. That was enough. I didn't want to push too much, especially for my "new student."
Afterwards I wrote out the song and "vocabulary" for the "new girl" to take home and study.