Camisola vs. suéter
The choice between camisola and suéter depends almost entirely on regional usage. In Portugal, camisola is the standard term for a sweater or sports jersey, whereas in Brazil, it usually refers to women's sleepwear. Meanwhile, suéter is the standard term for a warm knitted top in Brazil.
Camisola
A1In European Portuguese, camisola is the general word for a sweater, pullover, or a sports team jersey. However, in Brazilian Portuguese, camisola refers exclusively to a nightgown or nightie worn by women for sleeping.
A minha avó tricotou esta camisola de lã para o Natal.
(My grandmother knitted this wool sweater for Christmas. (European Portuguese context))
O Cristiano Ronaldo assinou a camisola oficial da equipa.
(Cristiano Ronaldo signed the team's official jersey. (European Portuguese context))
Ela vestiu a camisola de seda antes de apagar a luz.
(She put on the silk nightgown before turning off the light. (Brazilian Portuguese context))
Tirei a camisola porque estava com muito calor.
(I took off my sweater because I was very hot. (European Portuguese context))
Suéter
A1Suéter refers to a knitted garment for the upper body, typically made of wool, cotton, or synthetic fibers. It is the common term used in Brazil for a pullover. In Portugal, the word exists but is rarely used, as camisola covers this meaning.
Você deveria levar um suéter, pois vai esfriar à noite.
(You should take a sweater, as it will get cold at night.)
Ele gosta de usar suéter com gola em V para trabalhar.
(He likes to wear a V-neck sweater to work.)
Derrubei café no meu suéter favorito.
(I spilled coffee on my favorite sweater.)
Este suéter cinzento combina com tudo.
(This grey sweater goes with everything.)
Summary
To communicate clearly, use camisola for a sweater or jersey if you are in Portugal. If you are in Brazil, use suéter for a sweater and reserve camisola only for sleepwear to avoid embarrassing misunderstandings.