It is possible to write an impressive PhD thesis but then things can also go awfully wrong if you do not get a few things right. PhD thesis writing is not a talent. You do not need to be a native English speaker to write a great paper, all you need is the mastery of the whole concept of writing a thesis. Unfortunately, despite the fact that the basics are well known to many students, they keep going off the track every now and then because they fail to draw a line between the writing of an ordinary paper and writing a thesis, especially at such an advanced level as the doctorate level.