As a noun:
* The newly elected president made a pledge to improve the economy.
* The students signed a pledge to abstain from alcohol and drugs.
* The charity received a pledge of $1 million from a generous donor.
As a verb:
* I pledge to support you in all your endeavors.
* The candidates pledged to lower taxes if elected.
* She pledged her loyalty to the queen.
In a figurative sense:
* The storm clouds gathered, pledging a night of heavy rain.
* His silence pledged his guilt.
Remember that the meaning of "pledge" can vary depending on the context. You can use it to talk about promises, commitments, or even symbolic gestures.