I hope that I am understanding your question as I am interpreting it two different ways...
If you are asking which language your child should receive formal and informal instruction then I want to let you know that children are able to receive instruction in more than one language and usually be successful. For example, if you are a bilingual home (For example, Spanish and English), but your child goes to an English speaking school then it is fine to help your child at home in BOTH languages. Children often can process many languages in different environments.
Next, if you are asking how to praise your child verbally- simply use positive words such as "Great Job", "I am so Proud of YOU!", "I bet you feel happy for having a good grade or trying your best on this assignment".
I hope these responses answer your question!
Louise Masin Sattler, NCSP
Nationally Certified School Psychologist
Owner of Signing Families