Long before he boiled over, Virginia Tech gunman Cho Seung-Hui was picked on, pushed around and laughed at over his shyness and the strange way he talked when he was a schoolboy in the Washington suburbs, former classmates say.

Chris Davids, a Virginia Tech senior who graduated from Westfield High School in Chantilly with Cho in 2003, recalled that the South Korean immigrant almost never opened his mouth and would ignore attempts to strike up a conversation.

Once in English class, the teacher had the students read aloud and when it was Cho's turn, he just looked down in silence, Davids recalled.

Finally, after the teacher threatened him with an F for participation, Cho started to read in a strange, deep voice that sounded "like he had something in his mouth," Davids said.

"As soon as he started reading, the whole class started laughing and pointing and saying, 'Go back to China,' " Davids said.

Cho shot 32 people to death and committed suicide Monday in the deadliest one-man shooting rampage in U.S. history.

Stephanie Roberts, 22, a fellow member of Cho's graduating class at Westfield High, said she never witnessed anyone picking on Cho in high school.

"I just remember he was a shy kid who didn't really want to talk to anybody," she said. "I guess a lot of people felt like maybe there was a language barrier."

But she said friends of hers who went to Ormond Stone Middle School with Cho told her they recalled his getting picked on there.

"There were just some people who were really mean to him and they would push him down and laugh at him," Roberts said. "He didn't speak English really well and they would really make fun of him."

Regan Wilder, 21, who attended Virginia Tech, high school and middle school with Cho, said she was in several classes with Cho in high school, including advanced-placement calculus and Spanish.

She said he walked around with his head down and almost never spoke. And when he did, it was "a real low mutter, like a whisper."

As part of an exam in Spanish class, students had to answer questions in Spanish on tape, and other students were so curious to know what Cho sounded like that they waited eagerly for the teacher to play his recording, she said. She said that on the tape, he did not speak confidently but did seem to know Spanish.

Wilder recalled high school teachers trying to get him to participate, but "he would only shrug his shoulders or he'd give like two-word responses, and I think it just got to the point where teachers just gave up because they realized he wasn't going to come out of the shell he was in, so they just kind of passed him over for the most part as time went on."

She said she was sure Cho probably was picked on in middle school, but so was everyone else.

And it didn't seem as if English was the problem for him, she said. If he didn't speak English well, there were several other Korean students he could have reached out to for friendship, but he didn't, she said.

According to a school yearbook, Cho played a horn in the symphonic band in eighth grade. His yearbooks for ninth and 11th grades show he belonged to no clubs either year.

News reports from Korea said Cho had speech difficulties as a child.

Cho Seung-Hui left South Korea with his family in 1992 to seek a better life in the United States, Cho's maternal grandfather, identified only by the last name of Kim, told the Dong-a Ilbo newspaper. Relatives said they had minimal contact with the family after they left South Korea.

The 81-year-old Kim said Cho "troubled his parents a lot when he was young because he couldn't speak well, but was well-behaved," the report said.

Kim said he had little communication with Cho's family after they left for the United States.

"How could he have done such a thing if he had any sympathy for his parents, who went all the way to another country because they couldn't make ends meet and endured hardships," he asked.

Cho's parents have kept silent and out of public view since the shootings, with police keeping reporters away from their home in Centreville.

Staff writer Christina Rogers contributed to this report.