observe

Conform one's action or practice to.

Discover or determine the existence, presence, or fact of.

Show respect towards.

Behave as expected during of holidays or rites.

Follow with the eyes or the mind.

Make mention of.

“She observed that his presentation took up too much time”

Stick to correctly or closely.

Observe with care or pay close attention to.

Watch attentively.

“Please observe the reaction of these two chemicals”