Oto-Manguean
Western Oto-Mangue
Oto-Pame-Chinantecan
Chinantecan
Chinantecan Chinantec, an Indian language of southwest Mexico, is very hard for non-Chinantecs to learn. The tone system is maddeningly complex, and the syntax and morphology are very intricate.
Chinantec is rated 6, hardest of all.
Popolocan
Mazatecan
Lowland Valley
Southern
Jalapa Mazatec, another Indian language spoken in Mexico, has distinctions between what are called “modal”,”creaky”, and “breathy-voiced” vowels along with nasal versions of those three. It also has “creaky” consonants and odd things called “voiceless nasals.” It has three tones – low, mid and high. Combining the tones results in various tones that are called “contour tones.” In addition, it has a 3-way distinction in vowel length. Whistled speech is also possible.
It has a bizarre phonemic distinction between “ballistic” and “controlled” syllables which is only present only in Oto-Manguean languages and no where else in the world.
Ballistic (short)
sū – “warm”
nīˑntū – “slippery”
tsǣ – “guava”
hų̄ – “you plural”
Controlled (half-long)
sūˑ – “blue”
nīˑntūˑ – “needle”
tsǣˑ – “full”
hų̄ˑ – “six”
Jalapa Mazatec is rated 6, hardest of all.
Quechua and Guarani are 2 Amerindian languages still spoken by millions in South America. I wonder how hard they are.
I have some data on Quechua that I will put up later. It is not as hard as you might think!