Turkish is a language spoken by 65–73 million people worldwide, making it the most commonly spoken of the Turkic languages. Its speakers are located predominantly in Turkey, with smaller communities in Cyprus, Bulgaria, Greece, and Eastern Europe. Turkish is also spoken by several million immigrants in Western Europe, particularly in Germany. The roots of the language can be traced to Central Asia, with the first written records dating back nearly 1,200 years. To the west, the influence of Ottoman Turkish—the immediate precursor of today's Turkish—spread as the Ottoman Empire expanded. In 1928, as one of Atatürk's Reforms in the early years of the new Turkish Republic, the Ottoman script was replaced with a phonetic variant of the Latin alphabet. Concurrently, the newly founded Turkish Language Association initiated a drive to reform the language by removing Persian and Arabic loanwords in favor of native variants and coinages from Turkic roots. The distinctive characteristics of Turkish are vowel harmony and extensive agglutination. The basic word order of Turkish is Subject Object Verb. Turkish has a T-V distinction: second-person plural forms can be used for individuals as a sign of respect. Turkish also has no noun classes or grammatical gender. Turkic languages and Altaic languages Turkish is a member of the Turkish, or Western, subgroup of the Oghuz languages, which includes Gagauz and Azeri. The Oghuz languages form the Southwestern subgroup of the Turkic languages, a language family comprising some 30 living languages spoken across Eastern Europe, Central Asia. and Siberia. Some linguists believe the Turkic languages to be a part of a larger Altaic language family. About 40% of Turkic language speakers are Turkish speakers. The characteristic features of Turkish, such as vowel harmony, agglutination, and lack of grammatical gender, are universal within the Turkic family and the Altaic languages.There is a high degree of mutual intelligibility between Turkish and the other Oghuz languages, including Azeri, Turkmen, Qashqai, and Gagauz. History The earliest known Turkic inscriptions reside in modern Mongolia. The Bugut inscriptions written in the Sogdian alphabet during the First Göktürk Khanate are dated to the second half of the 6th century. The two monumental Orkhon inscriptions, erected in honour of the prince Kul Tigin and his brother Emperor Bilge Khan and dating back to some time between 732 and 735, constitute another important early record. After the discovery and excavation of these monuments and associated stone slabs by Russian archaeologists in the wider area surrounding the Orkhon Valley between 1889–93, it became established that the language on the inscriptions was the Old Turkic language written using the Orkhon script, which has also been referred to as "Turkic runes" or "runiform" due to an external similarity to the Germanic runic alphabets. With the Turkic expansion during Early Middle Ages (c. 6th–11th centuries), peoples speaking Turkic languages spread across Central Asia, covering a vast geographical region stretching from Siberia to Europe and the Mediterranean. The Seljuqs of the Oghuz Turks, in particular, brought their language, Oghuz Turkic—the direct ancestor of today's Turkish language—into Anatolia during the 11th century. Also during the 11th century, an early linguist of the Turkic languages, Ka?garl? Mahmud from the Kara-Khanid Khanate, published the first comprehensive Turkic language dictionary and map of the geographical distribution of Turkic speakers in the Compendium of the Turkic Dialects (Ottoman Turkish: Divânü Lügati't-Türk).

Psycholinguistics is the psychology of language and the study of the psychological and neurobiological factors that enable humans to acquire, use, and understand language. Psycholingusitics research makes use of biology, neuroscience, cognitive science, and information theory to study how the brain processes language. There are a number of subdisciplines; for example, as non-invasive techniques for studying the neurological workings of the brain become more and more widespread, neurolinguistics has become a field in its own right.The study of word recognition and reading examines the processes involved in the extraction of orthographic, morphological, phonological, and semantic information from patterns in printed text. Psycholinguistics covers the cognitive processes that make it possible to generate a grammatical and meaningful sentence out of vocabulary and grammatical structures, as well as the processes that make it possible to understand utterances, words, text, etc. Developmental psycholinguistics studies children's ability to learn language.

Paul Pimsleur (1928 – 1972) was an authority in the field of applied linguistics. He taught French phonetics and phonemics at the University of California, Los Angeles after obtaining his Ph.D. in French and a master's degree in psychological statistics from Columbia University. After leaving UCLA, Pimsleur went on to faculty positions at Ohio State University, where he taught French and foreign language education. At the time, the foreign language education program at OSU was the major doctoral program in that field in the US. While at Ohio State he created and directed the Listening Center, one of the largest language laboratories in the United States. Pimsleur was later a Professor of Education and Romance Languages at The State University of New York at Albany, where he held dual professorships in Education and French. He was also a Fulbright lecturer at the Ruprecht Karl University of Heidelberg, and a founding member of the American Council on the Teaching of Foreign Languages. He did research on the psychology of language learning and in 1969 was Section Head of Psychology of Second Languages Learning at the International Congress of Applied Linguistics. His research focused on understanding the language acquisition process, especially the organic learning of children who speak a language without knowing its formal structure. For this, he studied the learning process of groups made of children, adults, and multilingual adults. The result of this research was the Pimsleur language learning system. His many books and articles had an impact on theories of language learning and teaching. In the period from 1958 to 1966, Pimsleur reviewed previously published studies regarding linguistic and psychological factors involved in language learning. He also conducted several studies himself. This led to the publication in 1963 of a coauthored monograph, Underachievement in Foreign Language Learning, which was published by the Modern Language Association of America. Through this research, he identified three factors that could be measured to calculate language aptitude: verbal intelligence, auditory ability and motivation. Pimsleur and his associates developed the Pimsleur Language Aptitude Battery (PLAB) based on these three factors to assess language aptitude. He was one of the first foreign language educators to show an interest in students who have difficulty in learning a foreign language, while doing well in other subjects. Today, the PLAB is used to determine the language learning aptitude or even a language learning disability among secondary school students. Dr. Pimsleur died unexpectedly of pneumonia during a visit to France in 1972.

The Thai alphabet uses forty-four consonants and fifteen basic vowel characters. These are horizontally placed, left to right, with no intervening space, to form syllables, words, and sentences. Vowels are written above, below, before, or after the consonant they modify, although the consonant always sounds first when the syllable is spoken. The vowel characters (and a few consonants) can be combined in various ways to produce numerous compound vowels (diphthongs and triphthongs). Unlike the Chinese language, Thai is alphabetic, so pronunciation of a word is independent of its meaning . On the other hand, Thai is tonal, like Chinese and unlike English. This means that each word has a certain pitch characteristic with which it must be spoken to be properly understood. The Thai language uses five tones: mid, low, high, rising, and falling. Each syllable, consisting of one or more consonants and a simple or compound vowel has a default tone determined by several factors, including the type of consonant(s) present (consonants are divided into three classes for this purpose). The syllable's tone can be modified by one of four tone marks. The final tone of a syllable is determined by the tone mark in conjunction with the type of syllable, as determined by the vowel and consonant characters present.