The root շէն (shen) is a very productive one. If we have to believe tradition, it goes to the beginnings of the Armenian people. According to Movses Khorenatsi, the Father of Armenian history (fifth century A.D.), when Patriarch Haig left Babylon and settled in the Armenian plateau, he first founded a township called Հայկաշէն (Haigashen), meaning “built by Haig.” Here, shen is the root of the verb շինել (sheenel “to build”). It was also used with the meaning of “dwelling place.”
These two examples already show the ways shen may come up:
a) Unchanged, when it is the plural of Classical Armenian (շէնք – shenk “building”) or the second word in a compound word (Haig + a + shen );
b) Changed into շին (sheen) when the phonetic rule applies (է becomes ի) in the case of a compound or a derivative word, e.g. շինել (sheenel) – շինութիւն (sheenootyoon “construction”) - շինարար ( sheenarar “builder”).
This root has a second meaning: “prosperity.” For instance, you may have heard the expression Շէն մնաք (Shen munak). Of course, this does not mean “Remain built” (or… “You must stay,” according to Google Translate), because the word shen is only used with the meaning of “building” in a compound word. It is actually a blessing: “May you be prosperous” (“May you prosper”). The same meaning appears in the phrase Աստուած շէն պահէ ձեր տունը (Asdvadz shen bahe tser doonu), which we may translate as “May God keep your house prosperous.”
The difference between the two meanings “to build” and “to prosper” is marked by the application or not of the phonetic rule e > i . If you apply it, the root of the word means “to build” (շինել - sheenel); if you do not, it means “to prosper” (շէննալ – shennal).
At a colloquial level, it is interesting to note that many current speakers of Armenian tend to make a mistake that can even be labeled as funny. When they are talking about a construction, instead of saying շինութիւն (sheenootyoon), they tend to say շնութիւն (shunootyoon) . Besides forgetting the abovementioned phonetic rule, they also forget that shunootyoon does not come from shen, but from… shoon (“dog”). Before becoming all the rage, dogs were not very well regarded in language, whether in English or in Armenian. As a result, those wrongly using shunootyoon perhaps are labeling a construction as a doghouse (the first meaning of shunootyoon is “a dog thing”) or, even worse, as a place of adultery (the associative meaning of shunootyoon is “adultery”; the translation of the eighth commandment, “Thou shalt not commit adultery,” is Մի՛ շնանար /Mi shunanar).
The final advice would be: check how you use the language. Meanwhile, to paraphrase the Vulcan farewell greeting in Star Trek, “Build long and prosper.”