A singer's tongue can be their nemesis! We need it to articulate, but often we find that it has a mind of its own.
Becoming aware of what your tongue is doing of its own volition is the first step in getting it to do what you actually want it to do. Singers want their tongues to stay mostly relaxed, doing the minimum amount of work to articulate your words clearly.
Google "tongue and singing" and you will find a million different opinions on how to deal with your tongue when you sing. My students should be aware of how we approach it! Tip of the tongue behind your bottom teeth, to prevent pulling the tongue back and bunching it up. Exercises to stretch your tongue out are good to do, if you find it hard to keep your tongue from pulling back.
If you haven't already watched the
MRI of the opera singer
with me, check it out above! You'll see how active your tongue actually is while you are singing, without you even realizing it!