Many first time second language students feel that learning a new language is indescribably hard. Many have a "mental block" of sorts that prevents them from remembering new vocabulary, or even "hearing" words they have already learned.
The more astute students may even recognize that the problem is their own mental block, as opposed to the inherent difficulty of the material.
As an example, on vacation I recently met an American living in Spain, who admitted that he had a "mental block" to learning Spanish. He had essentially "decided" that Spanish was too difficult for him to learn, and thus he was unable to pick up even the simplest phrases, or even remember simple Spanish names (street names, restaurants, etc).
Other, more active students, I have interacted with, may have an academic mental block, which has convinced them that conjugations are "too hard," or that "French sounds too funny to understand," or other conscious or unconscious mental barriers to learning or remembering foreign material.
As a teacher or tutor of language students, how can I help them overcome this mental block?