Yes, there is another letter leads to a lot of pronunciation mistakes.  It is the letter G.  G can be pronounced two different ways.

The letter G can be pronounced as:

J in GEM

G in GOOD

How can you tell which pronunciation to use?  Just follow these rules:

If the letter G comes before I, E, or Y, then pronounce the letter G as a J sound.

If the letter G comes before A, O, or U, then pronounce the letter G as a G sound.