確かめる
たしかめる · tashikameru · JLPT N3 · verb-ichidan
to ascertain
🔍✅ 確か (tashika, certain) + める = to make certain
確か means sure or certain, and the ending める turns it into an action: making something certain. Related pair: 確かに (tashika ni) means indeed or certainly, and 確かめる means to check that it really is so.