Quote Originally Posted by Боб Уайтман View Post
If the sentence is logically unmarked (no special emphasis), there is a general tendency to put an object after a verb if the object is a noun:
Я вижу дерево. Я слышу музыку. Я не понимаю твоих слов. Я помогаю другу. Я знаю это уравнение.
And there is a tendency to put an object before a verb if the object is a pronoun:
Я его вижу. Я тебя слышу. Я тебя не понимаю. Я ему помогаю. Я это знаю.
This seems to be broadly consistent with the tendency to emphasize new information by moving it to the end of the sentence. Since a pronoun refers to an already-mentioned noun, by definition it's not "new," so it tends to be moved farther from the end of the sentence.