The limits of morphological structures may be defined as: All single morphemes, or combinations of morphemes of which at least one immediate constituents is a bound form (including bound alternants of free forms) and of which the peripheral immediate constituent is not a clitic, or combinations of free forms in nonsyntactic arrangements.
- Nida (1949), Pag. 105

The term 'word' cannot be conveniently used as equivalent of 'morphological structure', for it has too many other traditional associations.
- Nida (1949), Pag. 105