So many things wrong in this article it makes me doubt the rest of the (undeniably interesting) content.
- English does not have 5 vowels; depending on the variety that you speak and counting diphthongs it has about 20
- "phenology"?
- tonal languages, while challenging to learn for someone who doesn't speak one natively, are not that uncommon, and 4 tones (assuming they're counting correctly) isn't that many. Mandarin has 4. Cantonese has (depending on whom you ask) up to 9. There are American languages with 10-20
- English has 24 consonants by most counts (confusing the Latin alphabet with English phonology again), but there are African languages with famously many, many more than that
- "like Spanish, Navajo is a verb-centric language in which syntax centres on actions" - I'm not sure what that even means. Spanish, like Italian, is a pro-drop language which means you can drop the redundant pronoun if you want because the verb inflection tells you everything you need to know. Navajo is (depending again on who you ask) an agglutinative/fusional/polysynthetic language which, while weird to English speakers, is not that unusual (e.g. Turkish, Finnish)