Please can someone point out the essential difference between the following sentences:-

(1)   Dun akþam konsere gidemediniz mi?

(2)   Dun akþam konsere gidemezdiniz mi?

(3)   Amrikaya mektup yazmadýlar mý?

(4)  Amrikaya mektup yazamazdýlar mý?

Thank you.

Tazx1

1) couldn´t you go to the concert last night?

2) (are you saying) you couldn´t have gone to the concert last night? 

3) haven´t they write a letter to america?

4) (are you saying) they couldn´t have write a letter to america?

first of all, in a regular sentence, "soru eki" should be like I have corrected.

the difference between "gidemediniz mi" and "gidemez miydiniz" is that, in the first one it is asked if they couldn´t go (not sure if they went or not). In the second one, it is known that they did nto go, and it is asked if there was not any chance to go.

I think "Couldn´t you go to the concert last night?" can be interpreted in both ways so could be the translation for both. however, the second one could be better translated as "Wouldn´t you be able to go the concert last night?"

e.g.

Geçen yýl tatile gidemedim. (I was not able to go on a holiday last year; Maybe I had a chance but I did not go. )

Geçen yýl tatile gidemezdim. (I wouldn´t be able to go on a holiday last year. It was impossible for me - mostly because of things out of the person´s own control. it was clear that I did not have any chance)

please not that "-emezdim" could mean also in that way (although not in your examples):

18 yaþýndan önce tek baþýna tatile gidemezdi.

She was not allowed to go on a holiday herself before she was 18.

 unless you are quoting someone

gidemedi or gitmedi has one tense: past tense

gidemezdi or gitmezdi has two tenses: past tense and aorist tense

gidemedi is for one time event. he tried to go but he wasn´t able to do that (for that time; and he did NOT do it).

gidemezdi has a persistence, continuity. Something like "used to" in English. this -z suffix gives the word this meaning. gidemezdi; (maybe he wanted to do but) he was not able to do that (in that conditions for example, or for a while )

positive;

gidebildi : he tried and he could do that (one time; and he did it!)

gidebilirdi : he was able/allowed to do that (for a time period; and we are not interested in if he did it or not)

Thank you  ... silence, dilliduduk & caliptrix.

Tazx1