"Probablement no voy a entender"
I am going to be asking questions of a person who knows very little English and I know that I will not be able to understand everything that she answers. I want to say, "I probably am not going to be able to understand everything that you say (or tell me), but I am going to try. Is this correct? "Probablemente no voy a entender todo lo que tu dices, pero voy a intentarlo." Any suggestions for a better way to say it? Thanks.
I'd say "probablemente no voy a entender todo lo que (tú) digas, pero voy a intentarlo".
The "digas" is there because it's unknown what exactly she's going to say.
Try this is short and to the point also is gramatically correct ( at leat, I think so).
No entendere todo lo que digas. Pero hare el esfuerzo.
I think you should do something entirely different: put yourself in her (his) shoes. How would you feel if you came to me, and I said to you, "Oh dear...I probably won't understand you." Would that make you feel like talking? For me, I wouldn't want to talk. Porque no te lo guardas esta en tu bolsa, tengas paciencia con tu amigito, y vayan ustedes los dos juntos? Siempre se suele que con esa mente, los dos van apender algo bien!