Once again Turnoi, I agree with you up to a point. English is essentially a mix of Germanic and Latin with a few other snippets thrown in.

I think I may have mentioned that I have a keen interest in etymology so I am fully aware of certain spelling 'defects' and why they exist.

'Debt', for instance, has a silent 'b', but the word itself comes from the Latin 'debit'. The silent 's' in 'isle' or 'island' is not silent in 'islet' - the list goes on.

Another good example is 'choir' - why is it pronounced 'quire' ? etc, etc. etc.

I find that it also pays to know why English has direct synonyms that can be used in 100% of cases. Folk/People. Bowman/Archer. Liberty/Freedom etc,
and to know that words such as baggage/luggage can be interchanged except when talking about emotional baggage etc.

Then we can take that on step further and explain why there are at least 10 different synonyms that we can use in place of 'however', when used as a conjunction. = But, Yet, However, In spite of, despite, nonetheless, nevertheless, notwithstanding, although, even though, etc. - and why we would choose one over the others.

For the slightly higher level students, I find that lessons such as these are usually well-received in the classroom and can be fun to deliver.

I have developed a few ESL lessons on phonics. ESL students understand how pinyin works, so I just explain that it's 'pinyin English'. Often far easier to understand than phonetics, (especially for younger students), but it seems to work extremely well when the student writes down a word that is difficult to pronounce alongside the phonic spelling. If they want to know why it's spelt differently to the way it's pronounced, I tell them, but 90% of the time they don't seem to care as long as they know how to pronounce it correctly.