"I think of those clothes."
Translation:Eu penso naquelas roupas.
There are two reasons, either one of which eliminates "desses": (a) you can only use "desses" with masculine plural things and "roupas" is feminine plural; (b) In English we "think of" something but the literal translation "pensar de" doesn't work in this context and needs to be "pensar em" (and "em + essas" = "nessas"). You can also use the literal equivalent of "think about" = "pensar sobre" and in that case plain "essas" (or "aquelas") is fine.
I'm not a native speaker and I'm simply passing on what I've learnt from Brazilians such as moderator Paulenrique in discussions like this one: https://www.duolingo.com/comment/260546 :
[...] in Portuguese we use "pensar em" not "pensar de". Sometimes the prepositions don't match from language to language...
This is my question. It seems to me earlier we were trained to translate roupa as clothes. Do i remember wrong? So somewhere in our training, it would be helpful to learn the distinction in Portuguese between item of clothing and clothing. Regardless, both roupa and roupas should be acceptable if the distinction isn't clear in the English sentence.
In (Euopean) English we would never use "clothes" for the singular, we would state the type of the item eg "I like that dress", or "I like that coat". We wouldn't say "I like that clothes", and if we said "I like those clothes", we would never mean a singular item of clothes. The word "cloth" in English, only relates to a piece, or type of, material, not a material that has been made into an item of clothing.
The primary definition of "achar" is "to find", but it means "to think" when you're talking about your personal opinion. We sometimes use it the same way in English: http://michaelis.uol.com.br/ gives the example "acho difícil acreditar / I find it hard to believe." (Links to their definitions don't work in the comments here, but it's still a good dictionary. :P ) So you can say "eu acho que aquelas roupas são bonitas", but if the clothes are just on your mind, you have to use "pensar".
the rule is based on distance. Close to the speaker, este, estes (this, these); close to the person I'm talking to, aquele, aqueles (that, those), away from both, aquele, aqueles (that, those). Away in time, from the place, use aquele, aquela, aqueles, aquelas, aquilo.
These books in my hands are better than the ones you hold and are worse than those that Paul has at home. - Estes livros em minhas mãos são melhores que esses livros que você segura e são piores que aqueles que Paul tem em casa.
Why not 'daquelas'? BTW, why don't some of these comments match up with the questions? Does DL change the questions but keep the same comments? e.g. The comment under this one says "why not nessas instead of desses, which bears no relation to the question or its translation.