as in "I pride myself on my ability to speak Klingon and Romulan in the appropriate accents."
Which is the correct preposition for the end of that expression?
[Edited] The Oxford English Dictionary (2nd ed.) gives on pride (v.):
4.a. refl. To make or show oneself proud; to take pride, take credit to oneself, congratulate oneself; to plume oneself. Const[ructed with] on, upon, in (†for, of, about, with), that. Here are the examples it quotes - I left out the ones from before 1600:
1674 Boyle Excell. Theol. ii. ii. 138 The variety of inventions ... make us pride ourselves about things, that [etc.].
1691 tr. Emilianne's Frauds Rom. Monks (ed. 3) 361, I know ... Reason, why the Priests should pride themselves with this.
1756–7 tr. Keysler's Trav. (1760) III. 108 At Mantua, where they pride themselves not a little on account of their city being the birthplace of that great poet.
1806 Med. Jrnl. XV. 437, I prided myself that my hands had never been guilty of communicating that disease.
1807–8 W. Irving Salmag. (1824) 35 We pride ourselves upon giving satisfaction in every department of our paper.
a1849 H. Coleridge Ess. (1851) II. 146 The impotence of that which some women pride themselves in.
1850 D. M. Craik Olive I. v. 71 How Elspie then prided herself for the continual tutoring which had made the image ... an image of love.
1882 A. W. Ward Dickens iv. 91 He prided himself on his punctuality.
I only just consulted the 3rd edition, which presents a different picture:
3.a. trans. (refl.). Originally: †to show oneself proud, plume oneself (obs.). Later: to take pride in or congratulate oneself (for some achievement, ability, etc.). Now chiefly with on, that.
It has three new quotes as well:
1910 ‘H. H. Richardson’ Getting of Wisdom (1982) iv. 35 If there was one thing‥all of them prided themselves on, it was the good manners that had been instilled into them since their infancy.
1953 H. Clevely Public Enemy vi. 32 He prided himself that his voice sounded quite ordinary; he was giving nothing away.
1992 H. N. Schwarzkopf It doesn't take Hero p. x, For the entire first part of my career, I prided myself on being unflappable even in the most chaotic of circumstances.
I can't find any usage guides that specifically mention this. However, Google shows the following patterns:
So both "pride myself on" and "pride myself in" are well-attested, though "pride myself on" is the clear winner. The other options are an order of magnitude rarer, and probably indicate mistakes.
The one example I see in the Merriam-Webster definition of pride refers to "on":
I pride myself on [being or doing] something
Pride myself on... Take pride in..