This book presents diverse, original research studies on typical and atypical child language acquisition in monolingual, bilingual and bi-dialectal settings, with a focus on development, assessment and research methodology. Languages investigated in the studies include underrepresented languages, such as Farsi, Greek, Icelandic, isi Xhosa, Maltese, Mandarin and Slovene, without excluding representative work in major languages like English and Spanish. The language areas of focus are phonology, lexicon, morphology and syntax and the book incorporates studies in under-researched language impairment, such as Obstructive Sleep Apnea Syndrome and language impairment in 22q11.2 Deletion Syndrome. The book has practical significance in that it proposes tools and assessment practices that are of universal crosslinguistic relevance while also dealing with language-specific complications. The studies presented enhance existing knowledge and stimulate answers on what the acquisition of disparate languages in different contexts can teach us about language/communication development in the presence or absence of disorder.