> The biggest issue I see so far is the lack of checking of foreign teachers, I work with a few whose work sheets for the students are riddled with spelling mis

> The biggest issue I see so far is the lack of checking of foreign teachers, I work with a few whose work sheets for the students are riddled with spelling mistakes and bad grammar. Since we're on the subject of bad grammar, this sentence is a comma splice. You should replace the comma after "teachers" with a semicolon or a period. And I thought you were an English teacher!