8 Heb “the waters were going and lessening.” The perfect verb form הָיָה (hayah) is used as an auxiliary verb with the infinitive absolute חָסוֹר (khasor, “lessening”), while the infinitive absolute הָלוֹךְ (halokh) indicates continuous action.
9 Or “could be seen.”

In other versions

And the waters continued to abate until the tenth month; in the tenth month, on the first day of the month, the tops of the mountains were seen.

The waters continued to recede until the tenth month, and on the first day of the tenth month the tops of the mountains became visible.

The water continued to recede until the tenth month; in the tenth month, on the first day of the month, the tops of the mountains were visible.

Two and a half months later, as the waters continued to go down, other mountain peaks became visible.

And the waters continued to recede to the tenth month; in the tenth month, on the first of the month, the tops of the mountains appeared.

And the waters decreased continually until the tenth month: in the tenth month, on the first day of the month, were the tops of the mountains seen.

Public Domain