I think all of you grammar and spelling Nazis should be dragged out in the street and shot. You have no idea what it's like to endure an ambiguous grammar (finite automata dorks aside) because English, for all its woes, silent letters and pronunciation problems, is still relatively light on the homophones and homonyms.
Now let's talk about Semitic languages. Most Semitic languages follow a rule where there are two or three root consonants in a word with the vowels interspersed between them. But for rare cases where diacritics are written (usually for children), you don't know these vowels a priori. So you have to guess the meaning from context.
BNN, for example, can be Banana, Bonono, Bununu, Benani, etc. This can be significant in situations where the meaning changes through sound like so; "Ben" or "Bin" means "son of" where "Banu" means "sons of". For agglutinative languages like Hebrew, Arabic or Amharic, the structure of the language is regular enough that you can at least passably glean context from a sentence and pronouce/spell it correctly without pulling your hair out.
I am not lucky enough to speak one of these languages. Instead, I speak Farsi, which is an Indo-European language and thus very familiar to speakers of English, French, Hindi, Russian, Greek, etc. in structure; conjugated stems with prefixes and suffixes, a number of tenses, a series of noun and verb cases and all the stuff that I forgot about in high school Spanish.
This is also a language which -- save in Tajikistan -- uses the Arabic script, for which it is
wholly unsuitable. While sans-vowel homonyms in Arabic (or Hebrew, or Amharic) reflect 'variations on a theme' (bin/banu, for example), Farsi, like most Indo-European languages, has a damn lot of words look the same when you strip the vowels.
unrelated words. An english example: Bear, Bore, Bare, Beer, Boor. Take out the vowels and you have BR, and there is no
semantic relation between these words at all.
Thus, while reading a line of Arabic and you read "blahblahblah BN Ali' you can wager it's either about the son of Ali or the sons of Ali. It narrows down your search criteria and you can literally do a mental B-Tree search in your head to figure out the proper solution (for you computer science dorks, a NlogN scenario). Whereas in an Indo-European language, you can read "blahblahblah BR" and wonder if they mean bear, bare, beer, bar, bore, boor, etc. You can't use a search-based system; you will need an
Expert System. This can be exponentially more difficult to complete that word.
Now try it for many words.In addition, the historically Persian flair for calligraphy has bit the language a big chunk out of the ass. The Arabic language has four forms for their letters (instead of the Roman script's capitals, medials and ligatures.)
The first form is the letter as it is at the beginning of the word;
the second, for a letter in the middle of the word (that is then followed by another letter;
the third, for a letter at the end of the word that is attached to a previous letter; or a letter in the middle of the word that cannot have another letter attach to it -- in which case it is followed by
the fourth, for a letter at the end of the word that stands alone.
The third and fourth types of letters tend to be 'swishier' and 'flashier' than the boring middle types, so often times writers will put one of these two terminal letter types in the middle of the word and then resume the second word. Using our Western standard of capitals as a analogue, it would be saying something like:
AcheWood Is VeRy GoOd.
However, the word is considered one word, which is damn difficult to parse unless you are an expert. There is even a Unicode character, the "zero-width joiner", which is a way of saying that:

is the same as

which is quite nonintuitive.
To sum up, you have to be an expert in the language to have a passing ability with it, and thus real grammar and spelling hate should be directed here, not to poor, misunderstood English.
Goddamnit you don't understand I come from
CIRCUMSTANCES