When should I use A or An before words starting with a silent k?

When should I use A or An before words starting with a silent k?

You should use "an" before words starting with a silent "k." The use of "an" is determined by the sound of the following word, not the actual letter it starts with. Since the silent "k" does not produce a sound, it is treated as if the word starts with a vowel sound. Therefore, "an" is used before words starting with a silent "k" to maintain proper grammar and pronunciation.