I also asked Marc again about using -Ha' on adverbs. He said that if it makes sense, then -Ha' could be used. I offered the example of tlhIngan Hol neHHa' vIjatlh and he translated that as "I speak not only Klingon" as in "I speak many languages including Klingon". (Chris Lipscombe aka qurgh, July 28, 2017 after qep'a' 2017)

We previously saw neHHa' in 2017, when Dr. Okrand accepted the sentence tlhIngan Hol neHHa' vIjatlh as valid, and translated it into English as "I speak not only Klingon". But that Klingon sentence did not originate from him, and so some people don't consider it a "canon" example even though he okayed it. We now have [in the revised paq'batlh] a Klingon sentence using neHHa' that he composed himself. (David Yonge-Mallo in paq'batlh news, May 2022)