Because the super saiyan 4 transformation is a hybrid between a saiyans normal form and their ape form
Gohan is stronger if goku is in his normal form but if they are both in super saiyan 2 form or if Goku is in super saiyan form then goku is stronger.
Gogeta, the fusion of super saiyan 4 Goku and Vegeta.
Super Saiyan 2 goku cause he was able to defeat Broly as a Super Saiyan 1
Goku does not turn super saiyan 6 or 5 in fact. and it only goes up to super saiyan 3 in the manga and super saiyan 4 in the cartoon.
Goku can go up to Super Saiyan 4 there is no DB AF.
Yes each super saiyan stage is stronger than the previous for example super saiyan 2 goku is stronger than super saiyan goku although the second stage is slower than the first stage power wise it's an improvement super siayan 3 is stronger than 2 and faster as well super saiyan 4 goku is the fastest super saiyan form (of goku only not counting fusion with vegeta) and is the last duper saiyan stage goku reaches.
There is no Super Saiyan 5 it is limited to 4.
it has to be super saiyan 4 Goku but even better is super saiyan 4 Gogeta (fusion of Goku and Vegeta as super saiyan 4) even though it is a fusion they are still transformed saiyans.
you dont get him to be his form forever u need to get the orb in goku to go super saiyan
Super Saiyan 4 because that is the highest Super Saiyan level in the Dragon Ball official franchise.it is super saiyan 4 when kid goku turns gold ape then gets conscience and turns super saiyan 4
When his hair is black and it suddenly turns blonde it means he is A Super Saiyan.
his forehead is more visible in the SSJ2 form