It is often extremely hard to define the differences of meaning between allomorphs, since it depends solely on a difference in distribution. But our inability to correlate this difference with biosocial contrast does not invalidate [...] the basic assumption that we adopt as a premise for all descriptive analysis: that there are no actual synonyms.
- Nida (1948), a pag.431

[...] there are 'no actual synonyms' - no items that are different in form but absolutely identical in meaning.
- Nida (1948), a pag.431