Does the Money Sign Go in Front?

In English, the dollar sign is placed before the amount, so the correct order is $20, as others have noted. However, when you see people using 20$, it's likely they're being influenced by a few different things: Many other countries (and the Canadian province of Quebec) put the currency symbol after the amount.

Does the money symbol go in front or back?

When writing currency amounts, the location of the symbol varies by language. Many currencies in English-speaking countries and Latin America (except Haiti and Suriname) place it before the amount (e.g., R$50,00). ... In many European countries such as France, the symbol is usually placed after the amount (e.g. 20,50 €).

Does the Money symbol come first?

In most English-speaking countries that use that symbol, it is placed to the left of the amount specified, e.g. "$1", read as "one dollar".