Good day, all.
Concepts will be grouped from broadest terminology down to smaller minutiae, and then alphabetically within each sub-grouping. With all of these terms and categories, remember that these are only basic descriptions, not rules that must be written in stone; some languages use many different systems, to greater or lesser degrees, together and in different ways.
Broad-Category Definitions:
Allophone - Sometimes changing the phoneme in a word doesn't change the meaning, in the word 'Tuesday', the option is available to pronounce it with two separate phonemes which still have the same meaning; it can be pronounced as 'twosday' or 'Chyewsday' with the spelling of both using the letter 'T'. Therefore, the two different sounds are considered 'Allophones' of the phoneme 'T'.
Clause - When observing how languages express meaning, a 'clause' is the largest type of entity that can be used to express an idea or concept. What generally distinguishes clauses from phrases is that clauses have a subject and a 'finite verb', and phrases do not.*
*There is an exception to the rule about clauses and finite verbs, where clauses can use concepts such as 'non-finite' verbs, called 'Gerunds', and still be allowed within a language's rule system.
Inflection - There are two meanings here, either, the change in pitch or volume of someone's voice, or, the change in the shape of a word to indicate concepts such as tense, gender, mood, plurality, etc. Both definitions are used in linguistics, across different languages. The first definition would be relevant (mostly) to languages such as English, where we can make a statement into a question by changing the pitch and tone, but also tonal languages such as Mandarin. The second meaning would be applied, for example, to Romance and Slavic languages, but is definitely not limited to those language groupings.
Some languages inflect their stems with long chains of affixes, so that one word contains the meaning of an entire sentence in other language systems, these are called 'Polysynthetic Languages' because they have higher amounts of morphemes per word than other systems. Languages that use less sounds (morphemes) per word than polysynthetic languages, are called 'Isolating Languages'. If a morpheme, in an isolating language, has only one meaning (case-ending) per affix, the language is considered 'agglutinative', whereas languages where an affix can possess multiple meanings at once, are considered 'fusional'. Languages can be both poly-synthetic and agglutinative, depending on how they decide to structure themselves.
Morpheme - For this term, I like the Wikipedia definition because it is succinct, "A morpheme is the smallest meaningful unit in a language". There is an important distinction that needs to be made here, that words and morphemes are not necessarily the same thing, because different languages use different governing rules to dictate how meaning is expressed. Studying how languages can and do use different methods to create meaning is called the study of Morphology. Some languages allow single characters, or what we in English perceive as letters, to have meaning without requirement to be grouped with other characters; consider languages such as Mandarin, where a single character can have the meaning of a noun, verb, or other possible meaning, because it uses different methods to express meaning. English requires a full word in order to comply with our own grammatical rules, before it can be used in a sentence. In situations where a single letter is used to express something, such as expressing definiteness (a cat, a dog, etc.), the single letter requires a noun after it and therefore is not allowed to sit in the sentence by itself.
Morphology - As a general concept, morphology is the study of the method of how things take shape and what final form they take; in Linguistics, this process is translated as the study of words, the rules that govern their creation, and how different words act/react together in any given language. Examples of grammatical rules that are part of the study of Morphology are the use use of prefixes/suffixes, intonation (tone), stress of words and phrases, etc.
Phoneme - What exactly a phoneme is depends on the language, however, a phoneme is generally the sounds used in a language or dialect, where changing one sound in a word can change it's meaning. In so far as I understand, the speech sounds themselves are called 'phones', but become 'phonemes' when put together and applied to the rules of a specific language, to distinguish between words.
- Example: In English, if I say the words 'house/mouse', the letters '-H-' and '-M-' are phonemes that change the meaning of the word they modify. This means that, in languages such as English, the same letter wont always have the same sound whenever it is used. Traditionally, English has 5 vowels and 21 consonants, but most English dialects have, on average, 42-44 phonemes in their 'speech inventory', which is the entire library of sounds that can be found in a specific language or dialect.
- Example: In the word 'refrigerator' the '-o-' is generally pronounced with a different sound than in the word 'omega', because our language has developed in that direction; the phoneme '-o-' in 'refrigerator' is called a 'Schwa'. Schwas are found in many different languages, and are officially categorized as the 'mid central vowel' sound in the IPA's official charts, where the character is represented by an 'ə'. This means that, when looking at the IPA chart, you would pronounce it as 'refrigeratər'.
For reference, the 'O' in 'omega' is categorized as the 'close-mid back rounded vowel' sound on the IPA's charts, and is written in the IPA as 'O'.
Phrase - A feature available to languages, the smallest possible structure that can be used to express a complete thought or idea. Phrases are made up of words/morphemes that themselves require following the language's grammatical, morphological and morpho-syntactic rules.
Syntax - Once you understand how a language creates morphemes, the next step to understanding the flow of a language is understanding how sentences are created, this is called 'Syntax'. Syntax examines subjects like 'word-order', such as how in English phrases are organized in the sequence 'Subject, then 'Verb' then 'Object' or 'SVO' for short.
Types of Languages:
Now that you have an idea of some of the basic terminology, we will move on to less-generalized concepts, and begin discussing some of the different ideas that affect how languages use the above definitions. This grouping will feature definitions that roughly represent the final stages of language-understanding, before one actually starts creating sentences in one's target-language.
Synthetic Languages: Languages that determine meaning, based on the 'shape' of a word; in essence, I like to think of synthetic languages, using the analogy of 'chemistry'; You take base chemicals, mix and add other chemicals, to create new (synthetic) compounds, it is the same idea in 'Synthetic Languages'. In a synthetic language, the pieces that are added to base words, to create new meanings, are called 'Affix(es)'.
Synthetic languages use a system of 'cases' to determine what affix should be used, and when. Cases vary from language to language, but
- Agglutination: Agglutinative languages give meaning by attaching, 'gluing' several morphemes together*. Finnish and Hungarian are excellent examples of Agglutinative Languages. In terms of how words are built, agglutinative languages sometimes end up with incredibly long words, with multiple meaning-stems being added to the front, middle, or end of the base word that they are modifying, depending on the language being discussed. Agglutinative languages should not be confused with 'compounding' languages, which are languages, such as German and English, that take complete words and combine them with other complete words to make new ones. The easiest way to think of the difference is that compounded words can be separated and used by themselves, whereas the affixes of Agglutinative and Fusional Languages cannot be used in sentences by themselves.
- Fusion: This method of word-building will be familiar to most English speakers as the system used in most Romance and Slavic languages, where meaning comes from the changing or adding of letters/characters to the stem, called 'declension'. To express meaning, fusional languages take base stems (words) and modify them, permanently, with inflected case-endings; the base stem is still able to be combined with other case endings, in different situations, but if you remove the 'fused' affix, the word loses its new meaning.
Analytic Languages - This category is usually associated with languages such as English, Mandarin, Bulgarian and many others,