Ianto was muttering to himself in Welsh. It wasn't hard to work out that he was just making sure he understood what he was going over and that he didn't want anyone to know exactly what it was he was going over. Gwen knew what he was saying, but just left him to it. She really didn't need to know why the cream in the Fridge had gone far quicker than normal, so she tuned him out.
Jack watched Ianto from the bridge above the main hub. He was confused as to why the Welshman seemed to only speak to himself in Welsh, when there was another Welsh speaker in the office. He resolved to ask.
"Ianto?" Jack said as they walked into Jack's office later that day.
"Yes Jack?" Ianto replied.
"Why do you and Gwen talk to each other in English?" Jack asked.
"Gwen can speak Welsh?" Ianto asked, blushing furiously as he remembered her being within earshot when he was talking to himself about the cream.
"Yes," Jack said, before adding; "Don't all Welsh people"
"No Jack," Ianto said. "Surely you should know this?" When Jack shook his head, Ianto explained. "Only about 20% of Welsh people speak Welsh. English is the more common language, you've lived here for over a hundred years and don't know this?" Jack shrugged.
"Never seemed important," Jack said.