Question:
I inadvertedly ate some nuts on Ta’anis Esther, and after eating a couple of nuts, I realized it was a fast and stopped. Must i continue fasting today? Must I make-up the fast? If I must make-up the fast, when should i make-up the fast?
Answer:
You should continue fasting, but you can not say aneinu. Regarding making up the fast, please see the following link. https://dinonline.org/2018/12/18/fast-day-ate-by-mistake/
A frielichin Purim