How does Inflation reduce debt owed?

A little inflation is good, as it has shown countries with 0 inflation or less have fallen into liquidity traps. With higher inflation you would expect your own wages to go up increasing your buying power. With deflation the government would have less money to pay off the debt. You are basically looking at money buying power as with inflation people/government will have more money. As well with high inflation comes exchange rate depreciation. When the U.S. pays back their debt back in dollars other countries that may own it will get less of their currency back when they exchange it.