Mary was very observant to the rules of her new church.
She was an observant poet.
Observant:Those of many religious faiths are observant of the Sabbath and other holy days.Observance:Jews may show respect for God through observance of Shabbat.
"This is a ferociously short sentence."
He was very observant to see any movement.
You are very observant; I saw you looking at that bird.
Yes, the adjective observant usually means keen-eyed or perceptive.
to cut short
The crime spree was short-lived.
Use punchy, single-syllable words, and keep the sentence short.
You're is short for you are.
Aquarius who?
Religiously observant Jews will only eat kosher food.