Meanings of the Russian Preposition по

Did you know that the preposition по is one of the most used Russian prepositions, used with the Dative case, and that it can have several meanings?

1. Along, over, on, through

Машина едет по дороге. The car is going along the road.

Мы гуляем по лесу. We are walking through the forest.

2. Study specializations of various sorts (used with books and exams).

У меня есть учебник по географии. I have a geography book.

У меня экзамен по математике. I have a maths exam.

3. It is used to indicate something with which another object is in accord.

Поезда всегда ходят по расписанию. Train always arrive on schedule.

4. Means of information, post

Я хочу послать посылку по почте. I want to send the parcel by post.

По телевизору показывали интересную программу. There was an interesting program on TV.

5.  Cause or reason for something (negative meaning).

Извините, я вошёл сюда по ошибке. Sorry, I entered here bu mistake.

По болезни она пропустила важную встречу. Due to her illness she missed an important meeting.

6. Distributive sense

Они дали всем детям по подарку. They gave one present to each child.