This is the 3598th most frequent Japanese word.
追いつか
"追いつか" is the stem form of "追いつく" and means "to catch up" in English.
The verb '追いつかなかった' (oitsukanakatta) is used here in its negative past form to convey the idea of not succeeding in catching up or reaching the same level as someone or something.
彼は走ったが、結局追いつかなかった。
He ran, but ultimately did not catch up.
Here, '追いつく' (oitsuku) is in its plain present form, used to describe the act of keeping up or staying abreast with something.
進化のスピードに追いつくのは難しい。
It's difficult to keep up with the speed of evolution.
The potential verb form '追いつける' (oitsukeru) is used to discuss the possibility or ability to catch up to someone.