Punctuation Usage Errors
a. The Comma Errors There are many errors of comma usage found in the learners’ writing. Most errors are omission of a comma before yet or for conjunction in compound sentences. Addition errors of comma usage also occur when the learners put a comma before subordinate conjunction and no comma after it in complex sentences....
SENTENCE PROBLEMS IN WRITING- Misused Parts of Speech
The most frequent error of grammatical sentence problems is misused part of speech. Most learners omit a part of parts of speech in their sentences. Those happen because they do not have sufficient knowledge to use parts of speech in a sentence. The errors occured are omission, addition, misformation, and misordering errors parts of speech...

