“恍然大悟”常见的英文表达有 “suddenly realize”、“come to a sudden realization” 或 “have a sudden/clear understanding” 。以下为具体例句：
After listening to the explanation, he suddenly realized the truth.（听了这个解释后，他恍然大悟。）
She came to a sudden realization that she had been wrong all along.（她突然恍然大悟，原来自己一直都错了 。）
At that moment, I had a sudden understanding of what he meant.（那一刻，我恍然大悟，明白了他的意思 。）