and (4) Ich weiss nicht, I know not,
Wode's children, German-speakers acquiring English as a second language in the United States, produced some sentences showing apparent first language influence, such as
(5) John go not to the school.
What is interesting, Wode points out, is that they did not produce such sentences early on. Their first attempts at negation were similar to what one sees in first language acquisition, such as
(6) no, you (7) no play baseball.
They only produced sentences such as (5) when they had begun to acquire the aux. + neg. rule, i.e. when they had begun to produce sentences such as
(8) lunch is no ready.
Only then did they "fall back" on the more general German rule. Wode (1978, 1979) suggests that there is, therefore, a structural prerequisite for first language influence: the performer's interlinguistic structural description, his idea of the target language rule, must be similar to the structural description of the rule in his first language. Wode's children's English negation rule was not at all similar to the German rule in early stages, but it became similar when they progressed to the aux.-neg. stage. Hence, first language influence appeared later, but not earlier.
Also, consistent with his argument is the fact that sentences such as (5) are only found in child second language acquisition of English when the first language has post-verbal negation, as in Ravem (1968), in which the first language was Norwegian. Such sentences were not observed in other ESL studies utilizing different first languages (Milon, 1974, L1 = Japanese) and in studies of negation in English as a first language.
Kellerman (1978) suggests another condition for "transfer" to occur. The acquirer must perceive a similarity between items in the first and second language. Items that appear to be language specific (e.g. idioms) will be less prone to transfer.
These conditions are not contrary to the generalization presented here. It can still be maintained that we "fall back" on the first language when we have not acquired aspects of the second language. They show, however, that ignorance is not a sufficient condition for the occurrence of first language influence.