Translation guide
In Japanese, expressing 'several hours' depends on whether you are talking about a duration (how long something takes) or a point in time (how many hours from now or ago). The most common and versatile way is to use 数時間 (すうじかん) for duration. For 'a few hours', ２、３時間 (に、さんじかん) is very natural. When referring to a point in time, use 数時間後 (すうじかんご) for 'in a few hours' or 数時間前 (すうじかんまえ) for 'a few hours ago'.
Expressing that an action or state lasts for several hours.
The standard, neutral way to say 'several hours' as a duration. Suitable for both spoken and written Japanese.
The meeting lasted for several hours.
I waited for several hours.
Literally '2, 3 hours', this is a very common and natural way to say 'a few hours' or 'a couple of hours'. It implies a small, indefinite number, typically 2 or 3.
It'll be done in a couple of hours.
If I sleep for a few hours, I'll be fine.
Means 'some hours' or 'a number of hours'. It is slightly more vague than 数時間 and can be used when the exact number is unknown or unimportant.
I think it will take a few hours.
A more formal or literary expression meaning 'over the course of several hours' or 'for a period of several hours'. Often used in news reports or written narratives.
The power outage continued for several hours.
Expressing that something will happen or happened several hours from now or before now.
Means 'in a few hours' or 'several hours later'. Used for future events relative to now or a reference point.
I'll come again in a few hours.
The medicine starts to take effect after a few hours.
Means 'a few hours ago' or 'several hours earlier'. Used for past events.
He went out a few hours ago.
A more casual way to say 'in a couple of hours' or 'after 2 or 3 hours'.
I'll call you in a couple of hours.
Emphasizing that the duration is approximate, not exact.
Adding ほど (hodo) after 数時間 makes it explicitly 'about several hours' or 'approximately several hours'. It softens the statement and is very common in polite conversation.
Could you wait for about a few hours?
Using くらい (kurai) with ２、３時間 gives a casual 'about 2 or 3 hours'. Very common in everyday speech.
I took a nap for about a couple of hours.
数時間 (suujikan) is the most standard and neutral for 'several hours'. ２、３時間 (ni, sanjikan) is more colloquial and specifically implies 2 or 3 hours, often used for 'a couple of hours'. 何時間か (nanjikanka) is vaguer, meaning 'some hours' or 'an unspecified number of hours', and is common in spoken Japanese when you don't know or don't want to specify the exact number.
Do not try to directly translate 'several' as いくつかの (ikutsuka no) with 時間 (jikan). While いくつかの時間 is grammatically possible, it is unnatural and rarely used. Stick to 数時間 or ２、３時間.