Part 1. Procedures, Methods and Findings for Language and Its Disorders. The speech of fluent child bilinguals -- Speech production in simultaneous and sequential bilinguals -- Genetics and language -- Brain structure and function in developmental stuttering and bilingualism -- Part 2. Monolingual Language Diversity and Stuttering. The speech and language characteristics of developmental stuttering in English speakers -- Stuttering in Japanese -- Disfluent speech chacteristics on monolingual Spanish-speaking children -- Characteristics of developmental stuttering in Iran -- Stuttering research in Brazil: an overview -- A survey on traditional treatment practices for stuttering in Sub-Sahara Africa -- Part 3. Bilingual Language Diversity, Stuttering and Its Treatment. Review of research on the relationship between bilingualism and stuttering -- Stuttering in English-Mandarin bilinguals in Singapore -- Linguistic analysis of stuttering in bilinguals: methodological challenges and solutions -- Treating bilingual stuttering in early childhood: clinical updates and applications -- Methodology matters -- Part 4. Conclusions. Fluency disorders and language diversity: lessons learned and future directions