I can see your puzzlement, edrob, I understand.
where it reads
I'm not falling for that again nao seria melhor o uso going to?
You would expect something like "I´m not going to fall for that again".
And the same going to the examples of the show "Everybody hates Chris."
One problem we learners of English have, is the spoken English with all of those colourful and practical language ways.
That is, we go to school and learn from books.
The grammar books (and textbooks, but we can lump them togheter for practical purposes here.) give a "biased" towards the written language, leaving it as the yardstick to measure what is proper and standard in English.
The above examples, yours, are acceptable in the colloquial (street talk), one has to be acquainted with it and to know that it happens in everyday situations. That happens, they say, because it´s spontaneous, unplanned, conversational vocabulary. And of course it goes with the context.
It´s person to person conversation, one on one. Hence the er, mm, eh thing, that you don´t see/need in the written version.
There are English dictionaries that give tips or show that a word is more frequent in spoken or written form, and books on the subject.
For instance, the Cambridge Grammar of English - a Comprehensive Guide -Spoken and Written English Grammar and Usage . by Ronald Carter/Michael McCarthy.
Anyway, it´s better going step-by-step, wait to pass this bridge when you come to it. For the time being, you might read comics, novels, watch some movies, read the magazine "people" etc.
And when some "strange" word or sentence comes up, you "nudge" (cutuca) some buddy of yours on Facebook, English Experts, your teacher, and you will have your doubt cleared.