had been basing
- past perfect progressive of base.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Prof Andrew Hill wrote a positive review of anti-parasite drug ivermectin for treating Covid but reversed his stance once he discovered data he had been basing his conclusions on was untrustworthy.
From BBC • Oct. 13, 2021
