- Morpheme-based morphology, which makes use of an Item-and-Arrangement approach.
- Lexeme-based morphology, which normally makes use of an Item-and-Process approach.
- Word-based morphology, which normally makes use of a Word-and-Paradigm approach.
- Baudoin’s single morpheme hypothesis: Roots and affixes have the same status as morphemes.
- Bloomfield’s sign base morpheme hypothesis: As morphemes, they are dualistic signs, since they have both (phonological) form and meaning.
- Bloomfield’s lexical morpheme hypothesis: The morphemes, affixes and roots alike, are stored in the lexicon.
Comparison of American and British English
Formal and notional agreement
BrE: Spain are the champions; AmE: Spain is the champion.
- The past tense and past participle of the verbs
learn, spoil, spell, burn, dream, smell, spill, leap, and others, can be
either irregular (learnt, spoilt, etc.) or regular (learned, spoiled,
etc.). In BrE, both irregular and regular forms are current, but for some
words (such as smelt and leapt) there is a strong tendency towards the
irregular forms, especially by users of Received Pronunciation.
For other words (such as dreamed, leaned, and learned)
the regular forms are somewhat more common. In most accents of AmE, the
irregular forms are never or rarely used (except for burnt, leapt and
The t endings may be encountered frequently in older American texts. Usage may vary when the past participles are used as adjectives, as in burnt toast. (The two-syllable form learnèd /ˈlɜrnɪd/, usually written without the grave, is used as an adjective to mean "educated" or to refer to academic institutions in both BrE and AmE.) Finally, the past tense and past participle of dwell and kneel are more commonly dwelt and knelt in both standards, with dwelled and kneeled as common variants in the US but not in the UK.