מְלַל

Daniel 6:21 מַלִּ֑ל he spoke

Then Daniel replied, “O king, may you live forever!

Daniel 7:8 מְמַלִּ֥ל [was] speaking

While I was contemplating the horns, suddenly another horn, a little one, came up among them, and three of the first horns were uprooted before it. This horn had eyes like those of a man and a mouth that spoke words of arrogance.

Here: 'Speaking', an ongoing participle: a mouth that keeps talking. Verse 7:25 says what it talks about: 'words against the Most High'.

Daniel 7:11 מְמַלֱּלָ֑ה [was] speaking

Then I kept watching because of the arrogant words the horn was speaking. As I continued to watch, the beast was slain, and its body was destroyed and thrown into the blazing fire.

Here: A feminine participle, agreeing with 'horn': '[was] speaking', in progress. The horn is still talking when the verdict falls.

Daniel 7:20 מְמַלִּ֣ל [was] speaking

I also wanted to know about the ten horns on its head and the other horn that came up, before which three of them fell—the horn whose appearance was more imposing than the others, with eyes and with a mouth that spoke words of arrogance.

Here: A participle, 'speaking', describing continuing action: the mouth keeps on talking. In v.11 Daniel keeps watching 'because of the sound of the great words which the horn was speaking'.

Daniel 7:25 יְמַלִּ֔ל he will speak

He will speak out against the Most High and oppress the saints of the Most High, intending to change the appointed times and laws; and the saints will be given into his hand for a time, and times, and half a time.

Here: "He will speak". The form describes ongoing, characteristic speech, not a single outburst. It is a pattern of defiant talk.