A 'positive' statement in economics is a statement that can be verified or falsified. For example, stating that US inflation in February 2023 was 6.5% is a positive statement. This can be checked against actual statistical data.
In fact, according to the US Inflation Calculator it was 6.5%. So, although it was inaccurate, it was positive because it can be tested. This is in contrast to a normative statement which cannot be tested, such as 'inflation in the US is too high' which is a value judgment and normative.
See normative statements.