Parents love to teach their kids manners, but for a child that has a language delay, saying Please and Thank You is the last thing you should worry about. When a child is learning to put 2 words together, “(noun) please” does not count!

Instead, try using a (verb+noun) or (adjective+noun) when requesting and/or labeling.
“eat banana.”
“play ball.”
“read book.”
“drink juice.”
“blue blanket.”
“big puzzle.”

You want to introduce more  words into your child’s vocabulary. Saying “Please” at the end of each word isn’t teaching them new words. Once your child has mastered requesting and labeling independently using 3-4 word phrases, then it’s ok to introduce manners.