The number of letters in an alphabet depends on which alphabet you are referring to. Here are some common examples:

• English alphabet: 26 letters
• Spanish alphabet: 27 letters (including the letter ñ)
• Russian Cyrillic alphabet: 33 letters
• Greek alphabet: 24 letters
• Arabic alphabet: 28 letters

If you specify which alphabet you mean, I can provide the exact number of letters for that one!