How does the program counter work in a processor?

Question

Processors

From the book: "An instruction can take from 1 (opcode only) to 11 or more bytes if a 4-byte offset and a 4-byte operand are specified in immediate address mode, as well as 2 bytes of address mode and an opcode."
As I understand it, the processor needs to increase the program counter when moving on to the next operation. But if the instructions are of different sizes, how then does the processor find the start of the next instruction? And if the counter increases by 1, i.e. PC+1, how then are commands larger than one byte handled?

Answer 1

Calculates based on the current command.