The striker was the Black Cats' most expensive signing last summer, joining in a £6.8m deal from Dutch side AZ Alkmaar, but scored just one Premier League goal in his first year on Wearside and lost his place in the starting line-up towards the end of the campaign.
"It's a bit different [to Holland]," Altidore told the Evening Chronicle.
"Coming to Sunderland was a whole was different, but this is where you have to adapt.
"It was a tough year for me last year. I struggled, everybody struggled.
"When things don't go well, you analyse what you can do better. I've done that and hopefully this season I can start out on the right foot.
"The first year was difficult but it is out of the way now. We stayed up and now it is a new start for everybody and we just have to try and affect the game every time you play.
"When the team is playing well, you are going to see individuals playing well."
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