Good night vs Thank you

Hi,
My sister taught some words to my nephew e.g Thank you, Sorry, Good Night. His age is around 3 yrs.
So he was not able to pronounce Good Night correctly.
At night when my sister said him good night, he said " Good night is very difficult Can I say Thank you." ("मला गुड नाई़त कठिन वाटते, मी थंक्यु म्हटल तर चालेल काय ? ")
What can we say? Childrens are so innocent.
Have a nice day to all of you.