Question: According to the sequence of tenses in the following sentence, which should be used, 'is' or 'was'?

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> She got a well-paid job as she is/was proficient in both English and Chinese.
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Answer: 
Depends on the context.

If it is recent and the effects are still applied, I'd use *'is.'*

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> She got the job as she's proficient in both English and Chinese
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But, should it be a distant past, I'd use *was* (especially in storytelling).

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> He got the job as a gym trainer as he *was* very strong and in shape
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Although it seems logical to apply the present tense, which can imply a continuous state of being, to her dual qualifications of speaking both English and Chinese, the correct choice in context is to use the past tense of *was*.

The usage in the balance of the sentence is determined by the opening usage of what her qualifications *were* at the time, in the past, when she received the well-paid job.