Yak differences.

[Feu]

What are the outward physical distinguishing differences of the WWII Yak fighter variants please?

 

[CORSNING]

SOVIET COMBAT AIRCRAFT of the SECOND WORLD WAR. Vol.1
BY Yefim Gordon and Dmitri Khazanov.

My wife reminded me that my original answer was not the Christian
way. She was right so this is all I am allowed to post Feu.