Ever wonder who originally worked out the spellings for most of the words in the English language...and what the hell they were smoking? In Spanish, you pretty much pronounce all of the letters in a word with a few exceptions. In English...not so much.
Knife....and the K would be in there becasue?
Laugh,,,so, someone thought it would be cute to combine ugh and give it the F sound? Okay...
Let's have a letter...C... and give it both the S and the K sound when we already have those letters in the alphabet but oh yeah, let's make the K silent...see above.
I could go on and on.