Easy just bring him to life with the dragon balls,
Second time
Namek dragon balls!
goku comes back to life many times
while training with shenron goku turned back into a grown up by shenron powers
Well goku meets Goten but Goku was still dead at that point Goku was giving time on earth and Goten and Goku meet each other. The Goku has to leave but in the middle of the majin buu saga the the supreme Kai wishes him back to life to fight majin buu which he wins. (Goku leaves because he is out of time on earth)
Skips is goku ssj 8, who travel back in time.
yes
Goten was created to replace Goku as Akira Toriyama wanted to retire Goku from the series. However, Toriyama was forced to bring Goku back by the fans of the series.
No. Goku actually vanished. That's why when they tried to wish him back they couldn't
at first no, but Trunks comes back in time from the future to give Goku the antidote
When goku was back in his kid body he had his tail back, he was exposed to the moon and turned into a great ape. When Pan saw this she started crying, and goku saw this and the ape form calmed down and turned back to normal resulting in SSJ4
yes! he gets wished back with the dragonballs
i think it was after goku came back with his tail and turn ssj3 when he revert back to his old state goku look at the earth and become a golden great ape in episode 30. GOKU TURNED SSJ4 IN EPISODE 35, SHORTLY AFTER HE WAS A GREAT APE.
yes. After the goku turns to heaven dende and other warriors will have two chances to ask shenron in which one they can ask to go to namek's planet. On the namek's planet they should call porunga to get back goku alive. second wish is to return them to earth with goku. third wish is optional