Speaking during الطواف is جائز and does not invalidate it. النبي (صلى الله عليه وسلم) said: 'الطواف around the House is like الصلاة, except that Allah has permitted speaking in it. So whoever speaks in it, let him speak only good.' This hadith establishes that while talking is allowed, it should be purposeful and good speech rather than idle chatter.
The مستحب practice during الطواف is to engage in dhikr (remembrance of Allah), دعاء (الدعاء), istighfar (seeking forgiveness), and القرآن recitation. You may supplicate in any language — Arabic is not required for personal الأدعية. There are no specific mandatory الأدعية assigned to each circuit, despite what some printed الطواف دعاء booklets may suggest. Those circuit-specific الأدعية are later compilations, not from النبي's practice. The only السنة-specific دعاء is between the Yamani corner and the الحجر الأسود: 'Rabbana atina fi'd-dunya hasanah wa fi'l-akhirati hasanah wa qina adhab an-nar.'
Brief necessary conversation with companions — such as coordinating meeting points, checking on someone's well-being, or answering important questions — is fine. However, extended worldly discussions, arguments, gossiping, phone calls about business, and loud talking that disturbs others should be avoided. Use the precious time of الطواف to connect with Allah through heartfelt الدعاء.