which

I'm feeling kinda thirsty, which I do have some beer in the fridge.

From Middle English which, hwic, wilche, hwilch, whilk, hwilc, from Old English hwelċ (“which”), from Proto-Germanic *hwilīkaz (“what kind”, literally “like what”), derived from *hwaz, equivalent to who + like. Cognates include Scots whilk (“which”), West Frisian hokker (“which”), Dutch welk (“which”), Low German welk (“which”), German welcher (“which”), Danish hvilken (“which”), Swedish vilken (“which”), Norwegian hvilken (“which”), Icelandic hvílíkur (“which”).


which

Which song shall we play?

They couldn't decide which song to play.

Which one is bigger?

Show me which one is bigger.

(interrogative) What, of those mentioned or implied.

Take which one you want.

You may go which way you please.

After glaring upon the smoking philosopher, who took his misfortunes with such positive nonchalance, he growled out an oath in German, which language is particularly adapted for growling in; then, raising his hand, he dealt him a blow on his pipe, which sent it, like a rocket, into the midst of the players.

1860, Alfred Henry Forrester, Fairy footsteps, or, Lessons from legends, with illustr., by Alfred Crowquill, page 166 (Google Books view)

Whitaker’s blog post, housed on a website called Minutes Before Six, goes on to make references to Albert Camus’ 1947 classic, The Plague, dips into a Camus-inspired existential ramble and returns to an attempt to convey the detail of Prieto’s being essentially “noble,” which fact, he admits, will be lost in translation to anyone unfamiliar with death row units.

2015 January 21, Texas Public Radio, “Voices From Death Row: A Prisoner Writes An Ode To ‘Living Dyingly’”, in Texas Public Radio:

All the phones come in plastic bodies that have been given a brushed-metal finish and carry 64-bit processors from Intel, which fact they proudly announce with an Intel Inside logo on the back.

2015 May 2, Adarsh Matham, “Battle of the Smartphones”, in The New Indian Express:

He once owned a painting of the house, which painting would later be stolen.

Yesterday, I met three men with long beards, which men I remember vividly.

For several seconds he sat in silence, during which time the tea and sandwiches arrived.

I'm thinking of getting a new car, in which case I'd get a red one.

(relative, formal outside certain phrases) Designates the one(s) previously mentioned.

cilën

(interrogative) what, of those mentioned or implied

cili

(relative) designating the one(s) mentioned


which

Which is which?

By now, you must surely know which is which.

Which is bigger, the red one or the blue one?

I'm unable to determine which is bigger.

Which of these do you want to keep?

Which of these banes of modern business life is worse remains open to debate. But what is clear is that office workers are on a treadmill of pointless activity. Managers allow meetings to drag on for hours. Workers generate e-mails because it requires little effort and no thought. An entire management industry exists to spin the treadmill ever faster.

2013 August 17, Schumpeter, “In praise of laziness”, in The Economist, volume 408, number 8849:

(interrogative) What one or ones (of those mentioned or implied).

Please take which you please.

(not in common use) The/Any ones that; whichever.

Flour contains starch, which is a type of carbohydrate.

I found my camera, which I thought I'd lost, under the bed.

I entered the room, at the far end of which was a small table.

Sunning himself on the board steps, I saw for the first time Mr. Farquhar Fenelon Cooke.[…]A silver snaffle on a heavy leather watch guard which connected the pockets of his corduroy waistcoat, together with a huge gold stirrup in his Ascot tie, sufficiently proclaimed his tastes.

1897 December (indicated as 1898), Winston Churchill, chapter II, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd., →OCLC:

There was a neat hat-and-umbrella stand, and the stranger's weary feet fell soft on a good, serviceable dark-red drugget, which matched in colour the flock-paper on the walls.

1913, Mrs. [Marie] Belloc Lowndes, chapter II, in The Lodger, London: Methuen, →OCLC; republished in Novels of Mystery: The Lodger; The Story of Ivy; What Really Happened, New York, N.Y.: Longmans, Green and Co., […], [1933], →OCLC, page 0091:

Many genes with reproductive roles also have antibacterial and immune functions, which indicate that the threat of microbial attack on the sperm or egg may be a major influence on rapid evolution during reproduction.

2013 May-June, Katrina G. Claw, “Rapid Evolution in Eggs and Sperm”, in American Scientist, volume 101, number 3:

non-restrictive relative clause
non-restrictive relative clause#English

(relative) In a non-restrictive relative clause, referring to something previously mentioned.

She had a young child, which cried incessantly.

(chiefly archaic) Used of people (now generally who, whom, that; which remains possible with words also referred to by it such as baby, child).

The front door was open, which concerned me.

He had to leave, which was very difficult.

She saved my life, for which I am eternally grateful.

Plastics are energy-rich substances, which is why many of them burn so readily. Any organism that could unlock and use that energy would do well in the Anthropocene. Terrestrial bacteria and fungi which can manage this trick are already familiar to experts in the field.

2013 July 20, “Welcome to the plastisphere”, in The Economist, volume 408, number 8845:

This is the letter which I received.

This is the letter in which he explains his decision.

Forasmuch as many have taken in hand to set forth in order a declaration of those things which are most surely believed among us...

1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, Luke 1:1:

restrictive relative clause
restrictive relative clause#English

(relative, sometimes proscribed, see usage notes) In a restrictive relative clause, referring to a noun previously mentioned.

The men which acompanyed him on his waye stode amased, for they herde a voyce, butt sawe no man.

1526, [William Tyndale, transl.], The Newe Testamẽt […] (Tyndale Bible), [Worms, Germany: Peter Schöffer], →OCLC, Acts: