Working knowledge/the working knowledge/a working knowledge

Hi. Please help. Are the following correct? The example sentences are for asking grammar questions and I don't know whether they are good sentences to use for the context they are used, especially no. 2.

1. The people who attend this course are likely to come out with 1) working knowledge/2) a working knowledge/3) the working knowledge of Spanish. -- I think putting the definite article "the" before the words "working knowledge" might come across as lending a sense of restrctiveness to the sentence, which might not be desirable, but I think it would be correct.

2. This job rquires 1) the working knowledge/2) a working knowledge of Spanish. -- I think not putting any article before the word "working" is not correct.