Let us move on from the previous post and ask the question I was asked the other day, "How can a Catholic layman be certain that his priest is not breaking the rules?" Three basic actions will enable this. 1) know the faith and what accords with the faith, 2) know the basic rules of the Mass, 3) find a parish where the current priest is obedient to the rules. If you do these three, then you will not need to have a PhD in liturgy to catch a broken rule. For most laity following these three rules, an abuse will be obvious, and when it is not obvious, then it will still "feel wrong" so you can delve deeper.
This is the extra layer of difficulty with a modernist Mass. What are the rules? Modernism says "be innovative; make stuff up". Thus, if priests are supposed to make stuff up, how would we ever know when we have crossed a line? I was protestant for years; this is exactly the way that many denominations think. This is also the exact way that those denominations degenerate into compromising the truth and eventually just give up the faith. With that as a standard, you could degenerate into complete apostasy and just think it was "a new way of doing Mass".
On the other hand, in a reverent Mass that focuses on obeying the rules, the people know what to expect. They know that the Creed is said on Sundays, and that the people kneel for the consecration. They know what accords with reverence and what does not. The few times when things really stand out different (Palm Sunday, Maundy Thursday, etc.) then those are easy to look up (especially with the many orthodox resources available on the internet).
Do you know how bank tellers are taught to recognize a counterfeit? By studying authentic bills. They never look at a counterfeit in their preparation. That way they know exactly what to expect, and a counterfeit stands out like a sore thumb. They see it and know to reject it. You need to study and know what is good and right and then you will see what is wrong more easily and clearly. Know the faith, and Christ will enlighten your heart and mind and help you reject those things that harm your souls.