Like Spanish pronunciation, spelling is a lot simpler in Spanish than it is in English. Just master a few key rules and you’ll really see the benefits in your writing marks!
First, there are no double letters in Spanish, except ll (when it’s pronounced “y”) and rr. Remember, there are single r’s too, so don’t make them all double. However, never be tempted to use a double “f” or “t” or “s”, for example, as you might find in English or French.
Second, if the word has a “th” sound, there are two options – c or z – but a bit of logic will help you work out which one to use. If it’s followed by e or i then use c. Otherwise, use z.