Telegraphic speech consists of very short (2-word) sentences spoken by children when they’re very young, I believe mostly between 1.5 and 2 years old but can be slightly older depending on development.
Example sentences:
1. Me eat.
2. Mom go.
3. Dog sleep.
Sentences consist of only ‘main words’, mostly verbs / nouns, with words like prepositions, function words, modals, etc. omitted.