Quite complex subject, actually not complex "extensive" is a better adjective...
Well, firstly I suggest searching old post at English Expert, below we have one of those sources of excellent matterial found here:https://www.englishexperts.com.br/forum/infinitivo-x-gerundio-quando-e-como-usar-o-ing-t10819.html
I will try to help a little bit, right!
-ING is mostly found in Verb tenses
, the so called "continuous tenses
" (nowadays "progressive tenses
at the beginning of a sentence;Nouns
, very common structure, for example: Human beings
, so on...;Adjectives
, lots of ajectives are formed using "ING" and that seems to be part of your question...
This movie is boring. O filme é chato.
She is captivating. Ela é cativante.
They are amazing. Eles são surpreendentes.
You are annoying. Você é irritante.
See, when we use an "ing" adjective we're referring to "something that causes - boredom, irritation, annoyance...
If you are bored
(1-entediado) you' re not necessarily boring
(2-um chato). In this sentence we have two different adjectives 1-how one feels, 2-what one causes or how something/he/she makes you feel.
Nos seus exemplos temos:
Small change - como o PPAULO esclareceu, comumente é "troco, dinheiro trocado" é substantivo;
Small changing "pad" - small changing é adjetivo, qualifica o que vem depois (pad was my own contribution
) são aquelas mesinhas pra trocar o bebê.