I realized I was sounding like a broken machine after I took stock of how many times “things” slipped into my dialogue. Practically every other sentence it turned out. It appears ‘things’ is somewhat of a safety net for people learning a second language in adulthood. Since you are no longer an unburdened child ready to lap up all the vocabulary in the world, but rather battling a long list of essential acts needed for survival, thus vocabulary in another language takes a backseat.
Your sentences could also be littered with that pesky word ‘thing’. Rather than relying on “coisa”, there are alternatives ways to say ‘thing’ in Portuguese in a whole array of circumstances.
Below are substitutions for all those words that slip your mind or that you’ve not crossed paths with yet in the Portuguese language.
“Thing” for something Physical in Portuguese
Objeto – object
Produto – product
Peça – piece
Item – item
Spelt the same, but pronounced nasally at the end (read more here on common Portuguese pronunciation mistakes)
Aparelho – gadget, device, some sort of machine used to accomplish a task
Instrumento – instrument is used as a synonym of aparelho.
Coisinha – little thing
Ok, strictly not banishing the mundane “thing,” but a very Brazilian trait of adding the diminutive to a noun to take off the edge.

Something You Don’t Know the Specific Name in Portuguese
All the following are varieties of “Thingamabob” or “stuff.” In other words, slang and informal alternatives to “things” in Portuguese when you can’t recall the actual name.
Bagulho (also used to refer to cannabis … )
Tralha
Trem
Negócio
Parada
Troço
A Being or Something Unidentifiable in Portuguese
Ente – entity
Figura – figure
Ele é uma figura, means a person with a big or remarkable personality.
Entidade – body or authority
Ser – a living being
Using Thing for Something Abstract
Matéria – material or also used for stuff relating to a course. All stuff relating to a certain topic.
Assunto – the topic or the issue.
Tópico – the topic.
The “thing” we are going to talk about today.
O tópico/ assunto/ a matéria que nós vamos discutir hoje.
Questão – the issue or what thing we are focusing on. What needs to be solved.
Argumento – the argument in the sense of what someone is debating or protecting or supporting.

A Thing in Your Mind
Noção – notion
Pensamento – thought
Ideia – idea
Conceito – concept
A Further Way to Omit Thing in Portuguese
Many times, you can contract the adjective into the word thing for a more concise and more Portuguese sounding phrase.
O importante é que … | The important thing is that … |
O engraçado é que … | The funny thing is that … |
O pior é que … | The worst thing is that … |
O melhor é que … | The best thing is that … |
Also, substitute ‘assunto’ or ‘fato’ to refer to ‘thing’ in general.
O assunto é que … | The thing is that … |
O fato é que … | The thing is that … |