Be half the battle (won) phrase
To complete a very important part of the work in order to achieve a certain goal
If I can persuade my boss to accept my plan, that will be half the battle.
Having more than 700 people who completed the questionnaire was half the battle won. All we need to do now is to analyze the data then we can submit our report.
To become important or obvious
To finish or complete something in a satisfactory way
Used to describe something that has great influence or importance
The verb "be" should be conjugated according to its tense.
The expression dated back to the 18th century. It derived from an old proverb in Oliver Goldsmith’s comedy, She Stoops to Conquer (1773): "The first blow is half the battle."