Conditions affecting the ability to say specific words
If a player has difficulty pronouncing certain types of words, and it is preferable to the player to simply avoid them, then substitutions can be made, as well as the use of nonverbal cues. Develop strategies in conjunction with the player or caregiver to provide these substitutions or practices. It may be beneficial to be very specific about turn order. If preparation assists in a players ability to communicate, then properly understanding turn order may allow that lead time. Additional resources to more discreetly, yet effectively track turn order, could be the use of a visible tracking system, whether it be through tokens on a simplified chart, or some other tracking mechanism.
If the inability to say specific words does not impact understanding, and the player themself doesn’t show a concern, then it may simply be optimal to do nothing at all.