This is the 12106th most frequent French word.
témoignant
"Testifying" or "bearing witness."
In this sentence, "témoignant" functions as a present participle describing the act of testifying what was observed.
Le témoin a parlé vivement en témoignant de ce qu'il avait vu.
The witness spoke vividly while testifying about what he had seen.
Here, "témoignant" is used as a present participle indicating the action of expressing concern in the written message.
Elle m'a écrit un message, témoignant son inquiétude pour moi.
She wrote me a message, expressing her concern for me.
In this sentence, "témoignant" is applied as a present participle referring to the act of documenting or providing testimony of past experiences.