go back on
phr. v..phr. v.. to fail to keep a promise or an agreement you made earlier.
phr. v.. to fail to honour a commitment, promise, or agreement; implies a breach of trust or a reversal of a previous decision.
He promised to help me, but he went back on his word.
The government was criticized after they went back on their pledge to lower taxes.
Once the contract is signed, it becomes legally difficult for either party to go back on the agreed terms without facing significant penalties.
usually followed by a noun like 'word', 'promise', 'deal', or 'pledge'.
focus on the collocation 'go back on your word' as it is the most frequent usage; contrast with 'keep a promise' to show the antonymous relationship.
He went back his promise.He went back on his promise.the preposition 'on' is essential to connect the action to the specific promise being broken.