1. In the evenings, Sonya's father cooks dinner.
2. In the evening, Sonya's father cooks dinner.
3. Every evening, Sonya's father cooks dinner.
(What is the difference among the three sentences?)
All are fine and mean about the same thing, but I wouldn't use the phrasing in #1.
The difference among the three sentences lies in the use of different tenses and time adverbs.
1. "In the evenings, Sonya's father cooks dinner." This sentence indicates a habitual action in the evenings. It suggests that Sonya's father regularly cooks dinner during evenings, but it does not specify if it happens every evening or just on some evenings.
2. "In the evening, Sonya's father cooks dinner." This sentence also describes a specific action taking place in the evening, but it does not imply that it happens habitually. It simply states that on this particular evening, Sonya's father is cooking dinner.
3. "Every evening, Sonya's father cooks dinner." This sentence indicates a repeated action that happens every evening without exception. It emphasizes the regularity and consistency of Sonya's father cooking dinner every single evening.
In summary, the first sentence implies a habitual action in the evenings, the second sentence describes a specific action in one particular evening, and the third sentence emphasizes the regularity of an action happening every evening.