In English, some letters are not pronounced. For example, the letter ‘k’ in word knee is silent.  ‘K’ is usually a strong sound, like ‘kick’, but we don’t say ‘k’nee. The k is silent.  Other examples:

The ‘l’ in half or talk.  

The ‘h’ in honest.  

The ‘w’ in write.

The ‘n’ in autumn.

The ‘g’ in sign.

The ‘b’ in thumb.

The ‘t’ in listen.

The ‘u’ in guess.

Did you ‘k’now all of those?