[…] a simple code […] is nearer to the universal or underlying structure of all languages.
- Romaine (1988), Pag. 77

The initially acquired simple code becomes more complicated in ways specific to the actual language being learned.
- Romaine (1988), Pag. 77

[…] Corder [Corder, S. P. (1975). “Simple codes and the source of the second language learner’s initial heuristic hypothesis”, in Corder – Roulet (eds.), Linguistic Approaches in Applied Linguistics. Paris: Didier.] suggests that there are ‘simple codes’, among them baby talk, foreigner talk, pidgins and interlanguage. All of these are characterized by a simple or virtually non-existent morphological system, a more or less fixed word order, a simple personal pronoun system, a small number of grammatical function words and grammatical categories, little or no use of the copula and absence of an article system.
- Romaine (1988), Pag. 76-77