...and yet they are pronounced very differently.
/ˈslɔtər/ vs /ˈlɑːftə(r)/ For those who don't read 'pronunciation': Slaw-ter vs Laff-ter
Similarly: Homographs (words spelled identically but pronounced differently) run into the same issue for an English language learner.
After weeks in the desert the troops began to desert their fellows.
You can lead someone into a dark alley and then club them with a lead pipe.
She wound the bandage around his head wound (after he was hit with a lead pipe for deserting his fellows).
What is the best way to explain to a learner of English why the pronunciation differences exist and how to avoid the trap presented by homographs and other near-homographs (like s/laughter)?