Thai people who have low English skills do have little knowledge of correct
English grammar, they really cannot tell whether the signboards are effective or not.
In the circumstance where there is only the English signboards visible, if there are
some easy words that they can understand, that is enough for them to know what to
do. In summary, they do not care whether the signboards have errors or not; hence
they do not have the skills to tell them apart and do not think this phenomenon has
any significant to their everyday life.