[Serie: All About Japanese Particles]
1. Indicates an approximate amount or approximate maximum extent; in contrast with kurai and bakari, hodo tends to stress approximate upper limit: “approximately, about.”
Note: Kurai (#19, no.1) and bakari (#21, no. 1) may replace hodo in this usage, although hodo is somewhat more formal.
来月は、一週間ほど九州へ出張します。
Raigetsu wa, isshukan hodo Kyūshū e shuccho shimasu.
Next month I’ll be going on a business trip to Kyushu for as long as a week.
今度の事項で、100人ほどの人が死んだそうです。
Kondo no jiko de, hyakunin hodo no hito ga shinda sou desu.
I hear that some 100 people died in this traffic accident.
2. Indicates a comparison (used only in negative sentences): “as … as.”
Note: Kurai may replace hodo in this usage, but hodo is more common.
今年は去年ほど寒くないです。
Kotoshi wa kyonen hodo samuku nai desu.
This year is not as cold as last year.
あの人ほど頭のいい人はいないでしょう。
Ano hito hodo atama no ii hito wa nai deshō.
No one has as good a head as he has. / No one is as smart as he is.
3. Indicates the extent of an action or condition by citing a specific example: “so … that, to the extent that.”
Note: This usage is similar to kurai (#19, no. 2).
今日は勉強ができないほど疲れた。
Kyo wa benkyō ga dekinai hodo tsukareta.
Today I’m so tired that I can’t study.
試験に合格したので、うれしくて眠れないほどです。
Shiken ni gōkaku shita no de, ureshikute nemurenai hodo desu.
Since I passed the examination, I’m so happy that I can’t sleep.
4. Used in the form V-ba + V hodo: “the more … the more.”
北へ行けば行くほど寒くなります。
Kita e ikeba iku hodo samuku narimasu.
The further north you go, the colder it gets.
年を取れば取るほど、体が弱くなります。
Toshi o toreba toru hodo, karada ga yowaku narimasu.
The older you get, the weaker your body becomes.
– Source: All about particles – A handbook of Japanese function words –