As a Brit and mentor, but not a teacher, I would advise as follows:
Firstly, most spoken languages have a written equivalent.
Some, like "Gulf Arabic" (unlike standard Arabic, as used in books, newspapers, TV, radio etc), may not.
Through modern travel, people learn to speak some (or maybe more) of the vocabulary of the countries they visit.
Unfortunately, not many of those who do actually learn to speak a foreign language go that one step further and learn to read & write the written version of the language, particularly if the new language uses character sets not used in their native language (e.g. for Brits: Chinese, Japanese, Thai etc).
I hope this helps.
PS I'm currently struggling with the Thai language that:
has some 44 consonants,
28 vowel sounds (that can be written before and/or after, above or below the consonant(s) they follow in speech.
is a tonal language (i.e. the same word can mean many things, depending on whether it is spoken high, low, rising, falling or not) and
if a letter is at the end of a word it can be pronounced differently.
Just to add to the confusion, there are no spaces between words!
Please forgive us!