Yes, but the adverb "hardly ever" needs to contextualized if it appears at the end of a sentence. For example: Does he ever go shopping?
Well, hardly ever.
"Hardly ever" needs a complement to "complete" its meaning. The only way that it can appear at the end of a sentence (as in "Well, hardly ever") is that if the complement is "recovered" from the previous context (in this case, the question). In that case, what happens in that the complement is omitted, so you don't repeat it. The full sentence is: Does he ever go shopping?
Well, he hardly ever goes shopping.