The things she did with the stone were simple and small, if occasionally useful; the kind a child would imagine.

Crude work by current standards, but still occasionally useful.

NiCl and its hydrate are occasionally useful in organic synthesis.

It is occasionally useful to have the slave perform arbitrary and unpleasant acts.

It is occasionally useful to enlist the woman's aid in her own conquest.

His information about Britain, while occasionally useful, is not considered authoritative.

A promotion to knight is occasionally useful, particularly if it occurs with check.

A marginal but occasionally useful aspect of the media.

Stepladders are occasionally useful outdoors, but if you expect to be working near the roof, an extension ladder is a better choice.

Though all occasionally useful, in my music listening they came up less frequently than the need to correct pitch.