Best way to dynamically play animations

I am creating an app that will hopefully assist people in learning sign language(ASL). Currently I have an animation that does the whole alphabet, and then a bunch of smaller animations of each individual letter. The animations are played by pressing a GUI button which activates a trigger for the single letters and a bool for the longer animation. All animations will play as expected when their individual buttons are pressed.

the Issue I having is setting it up so that a user can select several letters dynamically and have each of the corresponding animations play.

As you can see, each of the animations go to and from the idle animation. The current setup plays the animation and then goes right back into idle mode. If it is possible I plan to setup a way for the user to be able to spell out any word, for instance if they select the letters for dog I want to have the d animation, then o animation, then g animation play before going back to idle. I tried transitioning between letters but the transition from a to b seems to play automatic- meaning when I click a it automatically goes into b

Any advice would be greatly appreciated.

When clicking animations, you should add the command to some sort of a queue. Then, when one animation ends, you should check the queue - if the queue is empty, go to the idle animation, if there is something in it, play it and remove it from the queue.