На столе лежал конверт, и я не сразу заметила, что на нём уже написан адрес.

An envelope was lying on the table, and I did not notice right away that the address was already written on it.

Breakdown of На столе лежал конверт, и я не сразу заметила, что на нём уже написан адрес.

• я: I
• стол: the table
• и: and
• на: on

Questions & Answers about На столе лежал конверт, и я не сразу заметила, что на нём уже написан адрес.

Why is it на столе and not на стол?

Because на столе means on the table in the sense of location.

• на + accusative often means motion onto something: положить на стол = to put onto the table
• на + prepositional often means location on something: лежать на столе = to be lying on the table

Here the envelope is already there, so Russian uses the location form: на столе.

Why does Russian use лежал here instead of something like был?

Russian often prefers specific verbs of position where English might simply say there was or was lying.

• лежать = to lie, to be lying
• стоять = to stand, to be standing
• сидеть = to sit, to be sitting

So На столе лежал конверт literally means An envelope was lying on the table. This sounds natural in Russian and often gives a more vivid picture than just using быть.

Why is конверт in the nominative case?