with or without "на"
Алекс готовился к экзамену месяц.
Они приехали в наш город на месяц.

These are two sentence from my testbook, I don't understand why "на" wasn't used in the first sentence but was used in the other.

Thanks for your attention

Question

with or without "на"
Алекс готовился к экзамену месяц.
Они приехали в наш город на месяц.

These are two sentence from my testbook, I don't understand why "на" wasn't used in the first sentence but was used in the other.

Thanks for your attention

Answer

Alex has been preparing for a month for the exam.
Them came for a month in our city.

Answer

the same in english
1. Alex spent a month for preparations
2. They came to our city on the weekend ( or for one month)

Answer

How long time made? - Месяц
For how long will be? - На месяц.

Answer

The first sentence says that he spent the month on studying . So we don't use "на". And in the second sentence they came and stayed FOR the month. So we use "на" in this sentence

لا تفوّت فرصة تعلّم لغة جديدة وأنت مرتاح في منزلك. تصفّح مجموعتنا المختارة من مدرّسي اللغات ذوي الخبرة وسجّل في درسك الأول الآن!