Alexander Skarsgard's seven-year-old co-star loved working with him because he's like a "human jungle gym".

The hunky actor got along famously with Onata Aprile when they were shooting What Maisie Knew. She was thrilled that he was always willing to play with him on set.

"I liked hanging on his arm!" she enthused to EW.com. "He's a human jungle gym!"

What Maisie Knew recently premiered at the Toronto Film Festival and is about a little girl whose parents are divorcing. Onata is Maisie, while Alexander portrays her mother's new boyfriend Lincoln.

Alexander was thrilled to work with Onata, who made every day a joy on set.

"I adore Onata. Even though I'm physically exhausted, I'm just so thrilled to be here," he said, after the premiere. "The whole thought of maybe not being here with her broke my heart. I hadn't seen the movie before the premiere, and neither did she. To see it with her was amazing. I love her, love working with her."

Alexander started working when he was seven, but took time away from the spotlight several years later. He was astounded by how skilled Onata was and is adamant she has a long career ahead of her.

"She's so sensitive, and real. I work for months, and I think about my character, I analyse everything. Then you show up on set, and she's a million times better than I am. I'm like, Come on!! This is not fair!" he laughed. "You work so hard, trying to sound and be natural, and she shows up and it's not at all false. It's all spot-on and real. She wasn't aware of the camera. She couldn't care less. When I got over the fact that this [then] six-year-old girl was so much better than me, it was so great, because that's what acting is, when you get so much from someone."