Here in this small audio lesson, you are about to catch up with the common and recurring mistakes which often pops up in classes. 

It happens amongst many basic and intermediate level students.  

The students often tend to add " TO " in between an auxiliary and main verb respectively.  This should be avoided at all cost. 

As a whole, it is a common and grave mistake. 

I reckon that you take notes of it and write few sentences to avoid it.

Hope it helps!