Translation:These are the dresses I am thinking of.
I am pretty sure that penser here means more than just thinking, such as considering, as in considering buying or wearing or cleaning etc.
In English, the past tense has more uses than just talking about the past.
Here the past tense is being used for politeness, but it can also be used to speak about the present and future in conditions.
As a native speaker "These are the dresses I was thinking of." clearly means you're still thinking of the dresses.
It's not 'debatable', it's merely the polite form. If you want to talk about things that happened in the past here, you need to use past perfect: "These are the dresses I have thought about".
I think it can be present tense. Like "These are the dresses I am thinking of taking on my honeymoon". It accepted my translation of "thinking about" instead of "thinking of". So that could be "These are the dresses I am thinking about returning to the store" or something like that.
you are right, but it French, you would need to change the construction:
ce sont les robes que je pense emporter en voyage de noces
ce sont les robes que je pense retourner au magasin.
so you see, "auxquelles" has disappeared, replaced by "que", which has become the object of verbs emporter/retourner and not anymore indirect objects of verb "penser à"
Not so, strictly speaking. Though almost no one distinguishes between them any more, formally you say "that" to specify the one thing out of several you mean, e.g.: "The horse that is black [instead of the horse that is white]". You would say "which" to describe further something already identified, e.g.: "The dog, which is barking at the squirrel".
That said, for Duolingo's purposes I doubt they should be picky.
Shouldn't the french sentence be "Ces sont ..." instead of "Ce sont..."? According to http://french.about.com/od/grammar/a/adjectives_demonstrative.htm I should be right. What's your opinion?
This is just my opinion . I find this part rather hard and I have the feeling that maybe it is not properly graduated for beginners . I daresay too many things all together. In Italy we say "Mettere troppa carne sulla brace" ( put to much meat on the barbecue = it will not be well done). I know that you are working hard and thank you for your useful help. :-)
It is the dresses that I am thinking about.
If that is not a potential correct translation, how would that be in French? I interpreted this as if the person was not actually seeing the dresses, but is only thinking about them. Someone asks them whether they're thinking about the shoes, and they reply: [No], it's the dresses I'm thinking about.
In my opinion, you need something more robust than a pronoun to achieve the plural to singular conversion, otherwise it just looks like a grammatical error, in either language.
Perhaps something along the lines of: "Les robes sont le sujet/cas/truc auquel je pense."
"C'est les robes auquel je pense." says the same thing, but it looks like a grammatical error even though the Object of penser à is singular.
In context, and with the addition of the word "No,", you can just about get away with using "it" in English, but you would have to ask a French native whether it works in French.