observar (verb)

Frequency star
  1. to observe, watch
  2. to notice, note
  3. to comply with, abide by (rules, laws)

Observé algo raro en su mirada cuando mencioné el dinero.

I noticed something odd in his eyes when I mentioned the money.

Todos los empleados deben observar las normas de seguridad en la fábrica.

All employees must abide by the safety rules in the factory.

El científico observa el comportamiento de los pingüinos durante meses.

The scientist observes the penguins' behaviour for months.