How to use 先 (さき)

Hello everyone,

I'm having a little bit of trouble figuring out how to use 先.
Tangorin provides several definitions including the point of a line, former, future, other side and destination.

If someone could provide some example sentences for each of the different meanings and explain how 先 is being used, that would be extremely helpful. The example sentences on Tangorin aren't making much sense to me, because I can't figure out what aspect of 先 they are referring to.

For example, how is 先 being used in this sentences?

• あの人はあまり先が長くない。 He doesn't have long to live.

Also, when would 先 be used as a prefix as opposed to a suffix or with の? When does it mean former as opposed to the future? What about the other reading せん?

Thank you in advance.

I use it a lot when I'm offering someone to go first. E.g.
お先に(おさきに) どうぞ after you.
When you are holding a door for someone say.
The main usage for せん is in 先生 せんせい。
彼女は先生です she is a teacher.
It can also mean ahead or before as in...
先週 せんしゅう last week.
先月 せんげつ last month
Etc.

ForestBird said:

If someone could provide some example sentences for each of the different meanings and explain how 先 is being used, that would be extremely helpful. The example sentences on Tangorin aren't making much sense to me, because I can't figure out what aspect of 先 they are referring to.

Click to expand...

http://dictionary.goo.ne.jp/leaf/je2/28663/m0u/先/

ForestBird said:

For example, how is 先 being used in this sentences?

• あの人はあまり先が長くない。 He doesn't have long to live.

Click to expand...

That's the third definition "the future" in the dictionary I linked above.
The future of that person is not so long. = He doesn't have long to live.

ForestBird said:

Also, when would 先 be used as a prefix as opposed to a suffix or with の? When does it mean former as opposed to the future?

Click to expand...

The context is the key, but ～の先 hardy (or never, perhaps?) means "former".

ForestBird said:

What about the other reading せん?

Click to expand...

http://en.wiktionary.org/wiki/先#Compounds_2
As you can see in the examples in Wiktionary, most of せん mean "former/previous" in compouds "先（せん）＋～".

So, essentially, 先 has the broad meaning of "ahead"; either ahead of time (in the past), ahead of an object (something up ahead), the place ahead in time (the destination), the point ahead of pencil, or an event ahead of now/another event (the future). Is that right?