By and large, the occurrence of errors is integral to the process of learning. The learning of languages (both the mother tongue and a second language), likewise, involves the making of errors. It is claimed and supported by research evidence that SLA errors are caused by both inter- and intra-language factors. Inter-lingual errors result from the negative transfer of a learner�s L1 features while intra-lingual errors are due to factors within the L2 itself like overgeneralization, ignorance of rule restrictions, incomplete application of rules, and false concepts hypothesized. Although both inter- and intra-lingual factors act as sources of errors in SLA, there is compelling evidence in the research literature that SLA errors are overwhelmingly L1 driven, i.e., mainly caused by the negative transfer of the language features of the first language of the learner. There is also strong evidence that first language interference presents itself to the learning of all aspects of a second language, i.e. morphology, syntax, semantics and discourse. The purpose of this paper is to briefly discuss the claims and views on L1 negative transfer to SLA; then to present secondary data in support of and as evidence for the claims with reference to the acquisition of the English syntactic properties of word order, subject-verb agreement, tense, copula BE, subject omission, the subordinate clause, expletive pronouns, positions of adverbs, and plurals among others; and, finally, to recommend an approach to the remediation of L1 induced English syntactic errors adopting form-focused instruction in tandem with meaning-focused, communicative activities. The evidence and examples of L1 transfer have been collected from diverse English language learning contexts and contexts of use which can be generalized to contexts other than those examined in the article.
SLA, L1 Transfer, Intralingual Influence, Syntactic Errors, Form- focused Instruction, Focus on Forms