Within the paradigm Quantity Theory of Money (QTM) framework, inflation is related to changes in the money supply, but this framework has been seriously challenged and cannot be taken at face value. If you plot a consumer price index for a particular country with the respective money aggregate over time, you’ll see that they are unrelated. However, QTM defenders say that the inflation is just delayed, for an unspecified period of time… empiricists are waiting for an inflationary response(or lack thereof) to expanding the money supply in 2008 in the US.

There is a handful of articles in the literature reviewing the instance of Quantitative Easing (QE) during the Great Recession and the apparent lack of impact on inflation, not supporting the QTM. Other frameworks attribute inflation to demand-pull and cost-push factors. All of this is good for further reading as it’s certainly a controversy in macroeconomics.