"I am a little child."
Translation:Je suis un petit enfant.
In French, most adjectives are placed after the noun.
Certain adjectives are placed before the noun, some which you can memorize with the acronym "BANGS":
Beauty - Age - Numbers - Good and bad - Size (except for "grand" with people)
These descriptors - and a few others - are considered inherent qualities of the noun:
- For example: "un petit enfant" for "a little child"
Here is Larousse's definition: