story identification - Two humans land on a planet; one learns to communicate with aliens

I read a book sometime between 1999 and 2002, possibly young adult. It starts out with a spaceship containing two astronauts landing on a foreign planet. One, a man, is rendered unconscious; the other, a woman, is the main (human) character. The planet has native life, including an intelligent species. Chapters of the book alternate being narrated by the female astronaut and one of the aliens. The point of the plot is depicting the woman and the alien as they gradually learn to communicate. I believe it ends with the woman and her injured partner leaving the planet after she has successfully learned to communicate with the alien.

At one point the alien is confused by the woman's spacesuit, thinking it is her real skin, and is surprised when she starts "shedding" it.

The alien also consistently refers to fingers as "digits", something that really confused me when I was a kid.

Answer

Might this be "Star Hatchling" by Margaret Bechard, published in 1995? It isn't a perfect match but it has some similarities.

In this book, it is one girl who lands on another planet - one that has a native intelligent species, which had not met humans. She interacts with, and learns to communicate with, two aliens (a boy and a girl, if that helps). Chapters alternate between the girl and one of the aliens, they learn to communicate, and they make mistakes and clear up miscommunications.

There is a scene where the alien mistakes her suit for part of her - removing her helmet makes the alien think she has lost (and quickly begun to regrow) her head, and I think once he sees her removing other parts of it he understands it as "shedding her skin". The alien species is lizard-like, so skin shedding is a familiar comparison to them.

The alien also specifically refers to fingers as digits. In the spacesuit scene, for example, he refers to a relative "losing and regrowing a digit" (a finger) as a way of expressing his amazement at how fast she "regrows" her head (and that she survived without one to do so). There are other mentions, too, I'm sure digit is the specific word used.

There is no injured, unconscious male astronaut tagging along with the girl and being rescued, the major difference from this book to your description. The main character is looking for another human, her mother, and so there may be a rescue plot - but I don't quite recall the details of the ending.

In the end there's several strong similarities and one fair-sized difference - so a partial match to your description. I hope it helps.