How to explain to 5 year old what a complete sentence is

Question

uri · Answer

*Complete sentence*

uri · Answer

When a period comes..

anonymous · Answer

a group of words that have a subject and a verb :)

anonymous · Answer

subject + predicate ( verb + object) + additional data could be called as a complete sentense.
example:
I am writing a reply : here I is subject which is pronoun, am writing is verb ( am is auxillary verb no need to tell 5 year old this much detail , just verb) and reply is object and all of these three which makes it complete sentence
you could have extra adjectives and adverbs and info like:
I am curiously writing this very little reply which i think would help you .:  here ''which i think would help you " is extra.

anonymous · Answer

okay, complete sentence is which starts with capital letter and ends with any of period (.) or question mark (?) or exclamatio mark (!)
importantly

anonymous · Answer

a sentence has a subject ,a verb and a punctuation mark at the end of the sentence. example:My dog ran. dog is the subject and ran is the verb and it has a period at the end.