Grammar for Everyone - Barbara Dykes 2007

Redundant adverbs
Introduction
Part II The parts of speech

Adding redundant adverbs is not only a form of repitition but it also diminishes the force of the verb itself. This addition appears to be made as a substitute for an object when the verb is being used intransitively (without an object).

Ask yourself whether the meaning of the adverb has already been expressed in the verb itself. If so, the adverb is superfluous.