Grammar JLPT Level N4 - Lesson 13

The adverb ほとんど is used in many situations in Japanese, and often translates as 'most', 'hardly any', 'almost all', and similar expressions. The nuance will always depend on the rest of the sentence. The most accurate translation for the word ほとんど itself is simply 'almost', where the thing that it is describing is always considered to be a full group, rather than a single thing.
As with many other adverbs that highlight an 'amount' in Japanese, ほとんど can modify a whole phrase, or can be used before の, to further specify a single noun.

• 宿題(しゅくだい)はほとんど終(お)わっているよ。
  Most of my homework is done.
• 弁当(べんとう)はほとんど食(た)べてないけど、おやつは全部(ぜんぶ)食(た)べた。
  I didn't eat most of my lunch, but I ate all the snacks.
• ほとんどの人(ひと)は私(わたし)の名前(なまえ)を読(よ)めません。
  Most people can't read my name.
• ほとんどの大学生(だいがくせい)は親(おや)と住(す)んでいます。
  Most college students live with their parents.

In negative sentences, ほとんど translates as 'hardly any'. This is mainly due to the 'full group' that ほとんど is describing being highlighted as almost 'not' existing.

• 今年(ことし)は屋台(やたい)がほとんどないね。
  There are hardly any food stalls this year.
• 週末(しゅうまつ)に出(で)かけることはほとんどないです。
  I hardly go out during the weekends.