This week’s seminar speaker (German, but currently working in the US) made several interesting pronunciation mistakes. Most notably, he kept pronouncing the verb interpret so incorrectly that I did not even recognize it immediately.
To understand what went wrong, we best look at the phonetic spelling. The are actually several pronunciations of interpret that are considered to be correct. The OED gives [ɪnˈtɜː(r)prət], where the r in parentheses is included only in American English. However, other sources (e.g., Longman) in particular include [ɪnˈtɜːprɪt], which will play an important role in the context of the aforementioned seminar speaker.
The phonetic spelling [ɪnˈtɜːprɪt] reveals several important details regarding the pronunciation of interpret. First, the stress (indicated by ‘) is on the second syllable. Second, the first e in interpret is pronounced as a long sound (ɜː), whereas the second e is pronounced as a short sound (ɪ). In strong contrast, the seminar speaker consistently pronounced interpret as [‘ɪntəprɪ:t], stressing the first syllable, pronouncing the first e short and the second e long. These three mistakes combined make it very hard to understand the word, so people had to rely on context. A possible origin of this mispronunciation is that the prefix inter- is pronounced very differently in words such as international [ˌɪntəˈnæʃnəl]. However, pronunciation rules in English are not entirely systematic, so that you should not extrapolate from one word to another.
As always, let me strongly suggest to follow the principle that your English is never too good to look up pronunciations in a dictionary. Doing so very often leads to interesting discoveries, even for native speakers.