Questions & Answers about Yazın göl kenarında kamp yaptık.
Here, yazın means in the summer or during summer.
It comes from yaz = summer, but in this kind of expression Turkish uses a special adverb-like form for seasons:
- yazın = in summer
- kışın = in winter
So in this sentence, yazın tells us when the action happened.
For seasons, Turkish usually does not use the regular locative ending -da/-de the way English uses in.
So instead of yazda, Turkish normally says:
- yazın = in summer
- yaz mevsiminde = in the summer season
- yaz aylarında = in the summer months
So yazda would sound unnatural in standard Turkish for this meaning.