Exactly: the action happened over and over again by definition because "Eu pensei MUITO em ti" . The action of thinking a lot is continuous by definition. "Eu pensei em ti" translates to "I thought about you", no doubt about that. However adding "MUITO" changes the action of thinking to something continuous.
If what you are describing were true then adding a lot to the English sentence would also require changing the verb to a continuous tense. However I thought about you a lot is correct English, just like Eu pensei muito em ti is correct and the most accurate Portuguese translation of the English original. Muito doesn't automatically trigger the need to change the verb to a continuous one.
I think there is a difference between English and Portuguese:
Eu estive/estava pensando is our past continuous. Present Continuous : Eu estou pensando:
• Ontem eu estive pensando no que você disse. (Yesterday I was thinking about what you said.)(Today I am thinking about how to explain what I thought.)
• Eu tenho pensado (I have been thinking) is our present perfect continuous.
• Eu tenho pensado em morar no campo desde o ano passado. (I have been thinking about living in the countryside since last year.) Here the action happened and still happens over and over again.
An easier example:
Meu cunhado esteve trabalhando em Newport no passado.(My brother-in-law was working at N. in the past.) Here the action happened for years – but ended in the past. - Now...Ele tem pescado...He has been fishing in São José every week.)
While I appreciate your response none of the above mentioned tenses are relevant to the sentence in the simple past provided by DuoLingo. The discussion centred around OP's erroneous assumption that muito or a lot require a continuous tense.
- Yesterday I ate a lot.
- Ontem eu comi muito.
Here we see that something happened once in the past - despite it happening a lot, it's still a one time occurence - thus the simple past is sufficient.
Ps. Is it me, or are there way too many tenses in Portuguese? ;(
Modern Portuguese Grammar: A Practical Guide by John Whitlam, specifically section 18.3.3 (iii) mentions this exact topic...
Also Google Translate:
com o verbo pensar é difícil pensar, pois não se sabe quando, ao certo, uma pessoa para de pensar, né? Em português, eu sei do que estou falando. Gostaria de saber em inglês, com um verbo em que a ação acaba claramente no passado. Trabalhar, por exemplo. Se foi uma ação contínua no passado, o inglês usa o present perfect continuous? Com uma data, inclusive?
Eu estive trabalhando nos EUA em 2002. Você traduziria como? I have been working in the USA in 2002. ou I was working in the USA in 2002. Please.
I don't like Google translator very much, but there is his translation:
with the verb to think it is difficult to think, because it is not known when, for sure, a person stops thinking, right? In Portuguese, I know what I'm talking about. I would like to know in English, with a verb in which the action clearly ends in the past. Work, for example. If it was a continuous action in the past, does the English use the present perfect continuous? With a date, inclusive?
Eu estava trabalhando nos EUA em 2002. How would you translate? I have been working in the USA in 2002. or I was working in the USA in 2002. Please, a I've been thinking yesterday - is it right?
I believe you are right, if the action actually ended. However think of "Nestas ultimas semanas, eu pensei muito em ti." I believe that it is perfectly OK to translate "During these last few weeks, I have been thinking a lot about you." Anyway what I learned from this discussion (and talking about it with Portuguese people) is that they very rarely use "Eu pensei muito em ti", but rather "Eu tenho pensado muito em ti", which is used much more in real life. Thanks for the entertaining chat !
Polska is also right ... I have been thinking could mean Eu estive pensando... For example: Maria, estive pensando, quer se casar comigo? - Maria, I've been thinking, do you want to marry me?
I thought a lot about what he said. Estive is past and usually means a finished past.
Eu estive construindo casas o mês passado = I was building houses last month.
Eles estiveram brigando na infância, agora estão casados = They were fighting in childhood, now they are married. (... they used to fight...)
So I concluded that he may be right, but it will depend on the context. We've been arguing, we've learned from each other.