HARDtalk speaks to Kenyan author, Ngugi Wa Thiong'o. He tells Gavin Esler that language plays an important role in hierarchies and systems of oppression.

He says that African authors should be clear about the fact that when they write in English they are contributing to the expansion of, and dependence on, the English language. He argues that translation plays an important role in allowing cultures to communicate but thinks it is "crazy" that a prize for African literature only considers books written in English.

Watch more clips at HARDtalk's website

You can watch the full interview on BBC World News on Tuesday 23 July at 08.30,14:30 and 20:30 GMT.