Each area of the world where English is spoken as a "native" language (USA, England, Australia, New Zealand,etc.) has its own special "inflections" and way that the words are accented or altered. Being a US citizen who grew up and lived as an adult in Asia (Japan), I have seen and heard many different accents from other foreigners as I lived and worked alongside many of them, and seen and heard the non-native speakers (mostly Japanese and other Asians there) struggle with comprehending the way each native speaker accented or altered different consonants, usually, to fit "the flow of the phrase being spoken.
I can't meaningfully respond as to the "inflections" of native speakers of other countries, but I have studied in-depth the ways that North American English can be hard to hear. But once you learn certain patterns that are very common, it becomes MUCH easier to understand. Dealing with the odd ways that the letter "T" morphs into different letters or even disappears, for example, can be very helpful. A simple phrase like "go to the store" can be hard to catch...as most people in the US say GO TO... like "GO-RU" (as it would be pronounced in Spanish or Japanese) and it is certainly no longer a "T" sound. more like a light "D" or Spanish "R".
Then when they continue with these mystery "T" letters bouncing around... when they say things like, "I've GOTTA (GOT TO / HAVE TO) "get out of bed" and "get some breakfast". Here there's a PAIR of mystery "T"s. GE ROU RA Bed (think Spanish or Japanese "R"), and then in the next phrase, the "T" almost "totally" DISAPPEARS when you say "get some". But please don't be scared by these. They are not as bad as they seem.
There are actually very solid patterns...in which you can almost guarantee which way the mystery "T" will go, and I have focused on teaching these because they are so important to hear and understand English as it is spoken here in the US. But the main thing is to have a general understanding of these patterns and then go on to learn the main phrases where they occur. Mostly they are the every day verbs like GO, GET, TAKE, HAVE, PUT, MAKE, etc. that are spoken in phrases that include these inflections, but they're not so strange once you see the patterns, and just focus on learning the phrases as a "package" and "go with the flow" of the sound of the phrase that includes the odd inflections. (for example, GO TO CLASS, GET UP, TAKE IT EASY, PUT IT IN [the oven, etc.], MAKE IT UP, etc. See below for clear categories of these patterns.) This is just a sample of some of the most common inflections...in this case, centered around the letter "T". I hope this helps you get more of a sense of "the flow" of language with its many "inflections".
(* SOLID PATTERN Examples: "T" after "N".tends to disappear...
as in RENTAL CAR, SANTA CLAUS or HUNTING.
* "T" before a vowel tends to go "light" as in Spanish "R"...
as in GO TO, GET IT (the first "T" only!),GET ON, GET IN, GET OVER, etc.PUT it ON, PUT OFF,etc.
* "T" before a consonant usually gets "silent" (or almost!) as in GET BEHIND, GET CAUGHT UP,
[but "GET AHEAD" is in the above "light" category...because it's followed by a vowel] )
