it seems like the sentence might have been cut off. If you're trying to say that someone was not only good at English, you could complete the sentence in several ways. Here are a few examples:

- Not only was he good at English, but he was also proficient in multiple languages.
- Not only was he good at English, but he excelled in all his subjects.
- Not only was he good at English, but he could write beautifully.

If you provide more context or complete the thought, I can help you construct a more precise sentence.