Phonemes
phoneme: A phoneme is the smallest contrastive unit in the sound system of a language.
Example: the sounds /t/ and /d/ are represented by the letters t and d are two english phonemes. The word cat contains three phonemes /c/ /a/ /t/.
Graphemes
grapheme: A grapheme is the smallest unit in a written language system representing a phoneme.
example: The letter k represents the sound or phoneme /k/ while the letter c is the grapheme that can represent the sound /k/ in the word cat or the sound /s/ in the word city. The letters sh represent one phoneme /sh/.
Word Structure
Syllables & Morphemes
syllable: a segment of speech usually consisting of a vowel with or without accompanying consonant sounds
morphemes: the basic building blocks of words and each morpheme has an associated meaning.
Etymology
Etymology: the history of a word or a morpheme. It can also help identify morphemes within a word.
Orthography
Orthography: The orthography of a language is the correct way to write in that language. The word itself is of Greek origin combining the words 'orthos', meaning correct, and 'graph', meaning to write or draw.