Some verbs end on -urre (condurre / to steer, produrre / produce, indurre / to induce, introdurre / to introduce, tradurre / to translate, ridurre / to reduce. Dire / to say is from this type as well).
All these verbs have one irregularity in the passato remoto.
regular but WRONG
lui / lei condurré
lui / lei condusse
In the other tenses the rr becomes a simple c (condurre => conduco). Not only the endings are irregular (co, ci, ce, ciamo, cono) but c is now followed sometimes by o (co, cono) and sometimes by i / e ( ci, ce, ciamo). Therefore the pronounciation is sometimes /k/ and sometimes /tsch/. (for details see chapter 2.5.)