I'm working mostly with non-native English speakers, and I it becomes apparent that sound-alike words often cause confusion, particularly in business emails.
There are too many of these words to make a separate question for each one:
to/too/two, brake/break, sail/sale, for/four/fore, buy/by/bye, hear/here, were/wear/where, pair/pear/peer, weak/week, seem/seam (I have also seen Siam in this context :), tail/tale, and many others.
I'm trying to nail them together by helping my friends and colleagues to learn them quickly and effectively.
I'm looking for an effective didactic method to help my colleagues grasp these words.
More details, if it matters: their native languages are primarily Thai and Chinese; many of them are working from homes, so it is not effective to buy books for each of them or arrange study in a school; most of them are rather familiar with formal and natural sciences, not humanities.