NASHVILLE — There are times when Aliyah Boston opens her mouth and is mortified by what comes out. There is no island lilt. There is no bounce to her cadence. Dahts and deys do not roll off her tongue. Never is never, not nevah.

She sounds so … American.

“Yeah, it’s embarrassing,” Boston said. “All my family can turn their accent on and off. But I, on the other hand, cannot do that at all. And they think I’m an embarrassment to our family because I can’t do that.”

As she explains this, Boston is giggling.

She is immensely proud that she grew up on St. Thomas in the Virgin Islands, which makes her American, of course. But she also knows that she may not be here — starring for the top-ranked University of South Carolina women’s basketball team and a national player of the year candidate — had she not left the island with her older sister Alexis when she was 12 and moved to the United States, where basketball has opened a world of possibilities.

The sisters moved in with their aunt, Jenaire Hodge, and her daughter, Kira, in their two-bedrooom apartment in Worcester, Mass., outside of Boston. This meant acquiring parkas, experiencing dark winters, and having to bury flip flops and shorts in their closet for most of the year. But it also meant an opportunity for Aliyah in basketball, exposing her to better coaching, better competition and a better chance of being seen by college coaches.

Boston was 15 the first time Coach Dawn Staley of South Carolina saw her play, at a tournament in which Boston’s team lost every game. Staley liked her agility, size and the way she talked to her teammates, but what struck the coach was Boston’s determination to keep going. “She was dog tired and, you know, bigs, when they get tired, just stop,” Staley said. “I vividly remember her never stopping. Even now, I see her and that’s who she is.”

Staley said that quality also speaks to Boston more broadly. She just keeps going.

Boston, 20, a junior who is a relentless force around the basket, has led South Carolina into an East regional semifinal on Friday against fourth-seeded North Carolina in Greensboro, N.C. She has run her double-figure streak in points and rebounds to 26 games and is eighth in the nation in blocked shots. South Carolina is taking aim at its second national championship after winning in 2017.

“She always seems aware of what she wants her legacy to be even from a very young age, and that’s uncommon,” said Staley, who noted that their conversations have always felt adult to adult. “She knows what she wants; she’s unafraid to ask questions. You can pour into somebody a lot more when they’re like that than when you’re trying to figure out: ‘What is that scowl on your face? What is that blank look?’ With Aliyah, she leaves nothing for you to assume.”

And so it made perfect sense when Boston’s parents, Cleone and Al, explained to Aliyah, who was entering seventh grade, and Alexis, who was entering ninth grade, that they would be moving to live with their aunt, Cleone’s sister. There were no tears about what they were leaving behind.

“I just thought of it as an exciting adventure,” Boston said.

As it turned out, it was not exactly both parents’ idea. The girls had been sent to their aunt that summer to attend a basketball camp. When they were away, Al took Cleone out to shop for new beds for their growing girls. She suggested he wait, but she did not stop him from buying them. A few weeks later, she informed him that the girls would not be returning.

“Mom and her sister colluded,” Al said. “They kept me out of the loop.”

“Terrible, terrible,” he added. “I can smile now.”

Said Cleone: “I had to pray a lot and hope God worked on his heart. He couldn’t see us not having the girls at that age.”

Ultimately, Al acceded because the plan had always been to use sports — Aliyah eventually chose basketball over tennis — to land a college scholarship on the mainland. (Alexis played at N.A.I.A. Thomas University this season, where she is completing a master’s degree.) The girls learned the game from their father, who on Saturday mornings would rouse them at sunrise and take them to practice on outdoor courts. (Indoor courts are rare and some remain damaged by Hurricane Irma, which walloped St. Thomas in 2017.)

Since there were only so many children playing organized basketball, boys and girls played together. “Parents would be in the stands and they wouldn’t want their sons to be outworked by a girl, so the boys tried to get physical with me,” said Boston, who towered over most boys then and has grown into a 6-foot-5 forward who relishes contact. “That’s why I started to love it the most.”

In Worcester, the girls stayed in regular contact with their parents. They had daily video calls, every-other-month visits, and persistent negotiations over whose rules they would be required to follow — their auntie Jenaire’s or their parents’. Their aunt liked to discuss matters, like sleepovers or sleeping in on Saturday; their parents liked to issue orders.

“I believe in a powerful voice,” said Cleone, whose daughters once woke up to find her in the living room, having flown to Boston to make sure they were washing the dishes, taking out the trash and doing whatever chores were needed to help their aunt, a single mother who was a running a catering business. “I’m a lot quicker to discipline than I am to talk. But I’ve evolved. I learned a lot from my sister.”

Earlier this season, Boston looked to her parents for comfort.

When South Carolina trounced Buffalo in an early-season game in the Bahamas, Staley chewed out Boston, who had 23 points and 7 rebounds. She wanted more from her.

“It wasn’t dominating; it was ‘you’re bigger than everybody else,’” Staley said. “I know I hurt her, but I wasn’t afraid to hurt her for where she needed to go. Every now and again, you have to poke her. She was like, ‘I don’t know what you want when you tell me to dominate?’ And I said I want them to stop using that clip.”

Ah, that clip.

One of the enduring images of last season’s women’s tournament was Boston collapsing in tears after she missed a last-second put-back that would have sent South Carolina into the championship game. Instead, when the ball rolled off the rim, Stanford won, 66-65.

“It happened,” Boston says now. “I can’t change it.”

Afterward, she received an embrace from her parents and Alexis. But Boston also received a text from someone who could understand the heartbreak — Tim Duncan, who, in 2013, missed a late shot and a tip-in that would have tied Game 7 of the N.B.A. Finals. Duncan, who said at the time that he would always be haunted by the misses, gained a measure of peace the next season when he helped San Antonio win the title.

In his message, Duncan, who grew up on nearby St. Croix, echoed what Staley had told her: How many players would have even been in position to fail? Seconds before, Boston had stolen the ball from Stanford near midcourt as the Cardinal was trying to run out the clock. She passed ahead to Brea Beal, whose transition layup rolled off the rim. Boston, who had hustled to chase the play, was there for the tip.

“Now probably if it’s me, after I gave it up I’m watching the play develop,” Staley said. “Again, she just keeps going.”

It was a rare occasion when Boston, bubbly and goofy and prone to breaking into dance, was not supplying the pick-me-ups. Her dyed braids, which are now orange with hints of white and gold, and her shoes, which might be any color in the rainbow, are expressions of her personality. “If she sees someone in a bad mood, it’s ‘Oh, do you want popcorn?’” said Beal, who lives with Boston. “Those little things make a big difference in how someone’s day goes.”

She is also proud of how she looks this season after shedding 23 pounds. “She’s showing more skin,” Staley said with a laugh.

The weight loss was part of a summer in which she worked with Duncan on reading the game from the post — the fruits of which were on display in a Southeastern Conference tournament win over Arkansas. When Boston received a pass on the block, she waited a beat to see how the defense would react. She then took a couple of dribbles, showed off an Hakeem Olajuwon Dream Shake and dropped in a Big Fundamental-esque jump hook over her left shoulder — an accent to her game that feels pitch perfect.