"zum Park" and "zum Markt" are appropriate in situations where you are saying you are walking TO the park or the market. But if you are saying you are going INTO them, then you say "in den Park" or "in den Markt". Its not mutually exclusive... it just depends on what you are trying to communicate.
I'm confused here. Previously, I had made some notes about going 'to' somewhere = change = accusative. z.b. Ich gehe in den Park. I am going "into", or "to" the park. I wasn't there before, but I will be. Whereas, Ich gehe im Park = I was already in the park and will continue to be, thus, I am walking in the park. So, if I understand correctly, I go to the park can be either accusative or dative depending on how it's written. Entweder "Ich gehe in den park" Accusative. Oder "Ich gehe zum park" Dative. Both imply movement, but even so, can be either accusative or dative, so, can we just choose how we want to say/write it?
There are certain prepositions that always take the dative case (aus, ausser, bei, mit, nach, seit, von, zu).
And also for accusative (dass, für, gegen, ohne, um, bis)
The rest of the prepositions (an, auf, in, über, etc.) depend on whether or not there is movement, so you're right! In those cases that's how you figure it out. But you need to memorize the prepositions that are only dative/only accusative.
Hope I help! :)
Plus a small three year late correction here :P
"entlang" actually only requires the accusative when used as a 'postposition' e.g. "ich laufe die Straße entlang"—as a preposition the most commonly used case is actually the genitive i.e. "ich laufe entlang der Straße".
According to Duden, the dative can also be used, but that is more rare than the genitive (in relation to "entlang"), and the use of the accusative case with "entlang" as a preposition is outdated.
Just a small, four year late correction :P
"dass" is not a preposition, it is a conjunction and therefore cannot take any case.
P.S. And there are also genitive prepositions (e.g. "wegen", "innerhalb", "bezüglich"), but I can understand them not being mentioned here to keep things simple :)
nach is used with cities or countries, but a park is neither.
See e.g. https://blogs.transparent.com/german/the-german-prepositions-%E2%80%9Czu%E2%80%9D-and-%E2%80%9Cnach%E2%80%9D-%E2%80%93-%E2%80%9Cto%E2%80%9D/ or http://germanisapieceofcake.blogspot.de/2012/04/zu-and-nach.html .
Prepositions such as to the, into etc. which one uses when describing a movement toward something are cofysing. zur-zum, ins, in den, nach, nach der, etc. (Ich gehe nach Hause-Ich gehe zur Schule.) Is there a definite rule or does one simply learn-memorize them as they come?
My feeling is that these contractions such as im, zum, ins, zur are essentially obligatory when the second part means "the".
I would usually say them as separate words only if I'm stressing the second word because I'm using it as "that" rather than as "the" -- so Wir gehen zum Park for "We're going to the park" but Wir gehen zu dem Park for "We're going to that park".
What is the diference between "zum" and "zur"?
zum is a contraction of zu dem.
zur is a contraction of zu der.
when must use which of them?
Try answering it yourself.
The preposition zu requires the ..... case.
In the ....... case, the masculine article der takes the form ......
In the ....... case, the feminine article die takes the form ......
In the ....... case, the neuter article das takes the form ......
So, given der Park "the park", die Bank "the bank", das Museum "the museum", how would you say:
- I am going to the park.
- I am going to the bank.
- I am going to the museum.
Feel free to refer to the "tips and notes" for this unit ( https://www.duolingo.com/skill/de/Dative-Prepositions/tips-and-notes ) as well as to the tips and notes for a unit not far back ( https://www.duolingo.com/skill/de/Dative-Case/tips-and-notes ).
Or to the "tips" for those two units ( https://www.duolingo.com/skill/de/Dative-Prepositions/tips , https://www.duolingo.com/skill/de/Dative-Case/tips ) which explain things differently.
I do hope you regularly read either the "tips" or the "tips and notes", e.g. by learning through the website https://www.duolingo.com/ rather than through a mobile app.