How many letters are there in the Greek alphabet?

There are 24 letters in the Greek alphabet. These are:

1. Alpha
2. Beta
3. Gamma
4. Delta
5. Epsilon
6. Zeta
7. Eta
8. Theta
9. Iota
10. Kappa
11. Lambda
12. Mu
13. Nu
14. Xi
15. Omicron
16. Pi
17. Rho
18. Sigma
19. Tau
20. Upsilon
21. Phi
22. Chi
23. Psi
24. Omega

Each of these letters has an uppercase and a lowercase form. The Greek alphabet has been used since the late 9th or early 8th century BCE and is still in use today. It is the script used for the Greek language and has also been used in the mathematical and scientific fields.