How do you speak pawnee?

Answer 1

You can not speak Iroquois, since there is no single language of that name. The Iroquois tribes each spoke their own different language and collectively these are members of the Iroquoian language family, just like Erie and Huron (among others).

Although the Iroquoian languages are closely related they are certainly not the same, as the following examples show:

English.......................Mohawk.......................Cayuga........................Oneida

red.............................onekwenhtara.............otgwęhjia...................onikwʌ́htalaˀ

deer...........................ohskennonton.............dewahǫhde.................oskanu·tú

arrow..........................kayènkwire.................ganǫh..........................kayu·kwíleˀ

So it is clear that nobody can "speak Iroquois", but they can learn to speak Oneida (Onyota'aka), Onondaga (Onoñdaʔgegáʔ nigaweñoʔdeñʔ), Mohawk (Kanien'kéha), Seneca (Onödowága or Onötowáka) or Cayuga (Gayogo̱hó:nǫ').

These are among the most difficult of all languages for an English speaker to learn, since there are so many non-English sounds and combinations of sounds which English speakers struggle to pronounce. These are represented by special characters in writing those native words. The Cayuga term for drifted snow, for example, is onyęˀgwaohǫh; this includes the non-English sounds ę, ˀ, and ǫ.

Answer 2

Unfortunately you can't, because there is no such language as "Indian."