There’s a palpable intensity to many of the characters Namir Smallwood inhabits onstage, from the posturing young tough of Northlight Theatre’s Charm to the paranoid soldier of Steppenwolf’s Bug. His flair for the passionate goes back, it turns out, to his first appearances in front of an audience growing up in Newark, New Jersey. “I had a talent for mimicry, and I used to learn Martin Luther King speeches, OK?” he says with a smirk. “I was 11 or 12 and started going around New Jersey doing these speeches at, like, Black history functions. I knew I had a gift because all the older people would be sitting there with tears in their eyes like they were reliving the ’60s. I was like, ‘Huh.’ ”

Smallwood’s latest role is less fiery but no less heartfelt. He’ll play Kenneth, a timid and seemingly traumatized bookstore clerk who spends his evenings at a tiki bar talking to an imaginary friend, in the Goodman Theatre’s Chicago premiere of Eboni Booth’s Primary Trust, the winner of the 2024 Pulitzer Prize for drama. “The thing that I find great about Kenneth is that Eboni doesn’t really give you a lot of backstory,” says Smallwood. “There’s a whole history that he has no idea of himself. And that’s true of a lot of people.”

An ensemble member at Steppenwolf since 2017, the Hyde Park resident feels settled in Chicago even as projects increasingly take him elsewhere. “My mother and grandmother always said, ‘All you have to do is just do the work. Do your best and things always work out.’ And they’re right.”

Primary Trust runs October 5 to November 3 at the Goodman Theatre.