PHILADELPHIA (AP) — A Jamaican farmworker who cannot read or write, and speaks with a severe stutter, has been in immigration custody for 15 months as judges try to resolve his case.Immigrants' rights advocates say 42-year-old Derrick Cotterel (KOT'-uh-ruhl) is vulnerable in prison.He speaks a type of Jamaican Creole, but his stutter makes it difficult for judges to understand him.The American Civil Liberties Union believes disabled immigrants like Cotterel need lawyers to get fair asylum hearings. But immigrants, unlike criminal defendants, don't have the right to free counsel.Immigration lawyer Craig Shagin (SHAY'-gun) has agreed to take the case pro bono while Cotterel fights deportation.Shagin says it's easy to take the ability to speak for granted — until you don't have it.