look back on

Inseparable

Definition

remember / reflect on

"I look back on my college days fondly."

The object must come after the particle: look up early. You cannot say look early up.

look aftertake care of look forsearch for look intoinvestigate look forward toanticipate with pleasure look upsearch in a reference / improve look outbe careful look down onregard with contempt look up toadmire