Question: To refer to the beneficiary or patient of an action, sometimes one can form a word using the verb and the *-ee* suffix, e.g. 

* assign → *assignee*
* employ → *employee*
* refuge → *refugee*

On the other hand, some forms like *givee* (the beneficiary), *killee* (the victim) or *massagee* (the one massaged) sound inherently stupid. I guess there probably are other *-ee* nouns that are at least that bad, but which I would unfortunately miss because of my poor English and wild imagination. Are there any usage rules or common-sense methods that would help me to distinguish between the proper, understandable words and the rest?

Any help or some references to on-line sources would be greatly appreciated.

Answer: 
The suffix *-ee* comes from the French past participle suffix *-é(e)*. There is a relatively short list of [English words ending with -ee](http://en.wiktionary.org/wiki/Category:English_words_suffixed_with_-ee), the vast majority of which are French or Latin in origin. I suppose *killee* and *givee* sound wrong because they’re of Anglo-Saxon origin, not Romantic, so the *-ee* suffix is less natural.

In general, I would avoid using *-ee* to coin new words, and further avoid using *-ee* words other than the most common, such as *employee*, *attendee*, *detainee*, &c. The silliest-sounding *-ee* words seem to be those using native English roots, where *-ed* is better:

> 
> \*The mugger mugs the muggee.
> 
> 
> The mugger mugs the mugged.
> 
> 
>
**All the comments that follow appear to me to be true of my English. No guarantee that they apply to others'. Comments welcome.**
Thinking about examples that I feel more and less happy with, I'd say that there are some prosodic constraints on *-ee*. 

In the best examples, *-ee* attaches to a root that has (i) two syllables, (ii) has, or can have, primary on the first syllable, (iii) has no long vowel in the second syllable. Your examples *assignee*, *employee*, and *refugee* all fit this description, as do *nominee*, *advisee*, and *conferee*. 

Note that, in the last two, stress shifts from its normal locus (*adVISE*, *conFER*) to the first (*ADvisEE*, *CONferEE*). This is why (ii) says "can have", not just "has". Some prefixes seem less able to accommodate this stress shift: *forgetee* is completely impossible for me, and *impugnee*, *repressee* are pretty iffy.

Nondisyllabic roots are (un)acceptable depending, again, in part at least, on prosodic factors. Two unstressed syllables before *ee* is problematic: witness such contrasts as *convertee* (imaginable) ~ *controvertee* (not), or *preposee* (imaginable) ~ *presupposee* (not). Similarly, one long syllable is also uncomfortable, as in your *massagee*. But *examinee* and *eliminee* are both fine for me, with the extra syllable occurring before the main stress.

When it comes to monosyllabic roots, if the root has a long vowel, I find the examples slightly better than if the vowel is short. I'm fine with *slayee* (a Buffy example), *callee* (cited above), *freeee* (it's about time we had a quadruple vowel in English), but not so happy with *givee*, *dropee*, *kickee*. To make the latter three vaguely acceptable, I find myself inserting a glottal stop between root and suffix (*kick'ee*, *etc.*).

That said, though, phonology is clearly not the whole story. I'm fine with *confutee* but unhappy with *confusee*, unhappy with *refutee* but fine, of course, with *refugee*. Or maybe I'm just tired...