monumental

当然のことかもしれませんが，Survival Englishに参加している生徒の真剣さは一般的なlearnerとは一線を画します。「生きるため」を上回る動機はありませんね。
名詞のmonument（記念碑）に由来するmonumentalには「記念すべき」という意味に加えて「とんでもない，巨大な」という意味があります（『スーパー・アンカー英和辞典』第4版，学研教育出版）。同辞書にはa monumental task（大仕事）が挙げられていました。（Koyamamoto）

Honduran Youth Finds Welcome Mat at Oakland School Designed for Immigrants
OAKLAND, Calif. — Above the bunk bed Lester Valladaras sleeps on each night, a collection of photos of his three younger sisters and his mother, Maribel Irias, is tacked to the wall. Ms. Irias made the collage during an English class a couple of years ago, before Lester came to America, writing this explanation next to the images: “I have three daughters here with me and two sons still in Honduras. I miss them very much. I hope they come here one day.”
… Lester is among nearly 100 students at Oakland International High School who traveled across Central America on their own in recent years. Oakland International educates recent arrivals, one of just a few such schools in the country. Just two years ago, only a handful of children were arriving on their own from Central America. Now, such students make up nearly a quarter of the school.
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But even here, at a school designed for new immigrants, there are deep challenges. Many of the students have not been in school for years, or at all — meaning that simple tasks like finding the right work sheet or assembling a binder can feel monumental.
http://www.nytimes.com/2014/11/09/us/honduran-youth-finds-welcome-mat-at-oakland-school-designed-for-immigrants.html?hp&action=click&pgtype=Homepage&module=photo-spot-region®ion=top-news&WT.nav=top-news&_r=0