We kept a substitutable in the supply closet for emergencies.

The coach substituted the injured player with a rookie in the final minute.

The chef kept several substitutes in the pantry for guests with allergies.

When the head chef is ill, the sous-chef substitutes him in the kitchen.

When comparing products, economists often analyze their substitutabilities to predict how changes in price will shift demand.

The assistant teacher stepped in substitutively to cover the lesson when the main teacher was absent.

The engineer suggested that the new component could be used substitutably in the existing design to simplify production.

The lab kept several substitutables on hand in case a sensor failed during the experiment.

When the committee couldn't find a permanent replacement, they appointed a substituter to handle meetings temporarily.

The substituters arrived early to learn the new procedures before the regular staff returned.