Learn Hardcore Russian: Вилка лежит на столе рядом с тарелкой. - The fork is lying on the table next to the plate.

Because the preposition на can mean “on” in two senses: static location (where?) and direction (куда?). For static location you use the prepositional case. стол → столе means “on the table.”

Why is тарелка in the form тарелкой instead of тарелке?

Because the phrase рядом с (“next to, beside”) consists of the adverb рядом plus the preposition с, and с always takes the instrumental case. So тарелка (nominative) → тарелкой (instrumental) after с.

What does лежит mean, and why not стоит or сидит?

лежит is the 3rd-person singular present of лежать, “to lie (horizontally).” In Russian you choose the verb of position by orientation:
• лежать for a horizontal object
• стоять for a vertical (standing) object
• сидеть for seated beings
A fork lies flat, so you say вилка лежит.

What part of speech is рядом, and why can’t I just say рядом тарелкой?

рядом is an adverb meaning “near, next to.” To attach it to a noun you need a preposition: рядом с + instrumental. You cannot skip с or switch to another case; the structure is fixed.

Could I use возле instead of рядом с?

Yes. возле is a synonym that takes the genitive case:
“Вилка лежит на столе возле тарелки.”
Both mean “beside the plate,” though рядом с｜instrumental and возле｜genitive are the standard patterns.

Why isn’t there a comma before рядом с тарелкой?

Because рядом с тарелкой is an integral adverbial phrase describing where the fork lies. There’s no pause or parenthetical—so no comma is needed.

Can I change the word order?

Yes—Russian is relatively free in word order. You could say:
• Рядом с тарелкой на столе лежит вилка.
• На столе лежит вилка рядом с тарелкой.
Each variation shifts the emphasis slightly but keeps the same meaning.

How would I ask “Where is the fork?” and answer in Russian?

Ask: Где вилка?
Answer: Вилка лежит на столе рядом с тарелкой.