* Sees Q2 GAAP loss

* Sees Q2 non-GAAP EPS $0.14-$0.16

* Reports Q1 adj EPS of 20 cents

* Q1 revenue up 41 pct

* Shares tumble as much as 14 percent in after-hours trade (Adds details from conference call, shares)

May 11 (Reuters) - Recently public Rosetta Stone Inc (RST.N: Quote, Profile, Research), a provider of software that helps users learn new languages, forecast a second-quarter loss due to a charge.

Its shares tumbled as much as $4.12, or 14 percent, to $25.35 in after-hours trade. The stock closed at $29.47 Monday on the New York Stock Exchange.

The company would incur a one-time compensation charge of associated with stock grants to key employees, Chief Financial Officer Brian Helman said in its first conference call since it went public last month. [ID:nWNAB7702]

Rosetta expects to post a second-quarter loss of 42 cents to 44 cents a share on revenue of $53 million to $55 million. Excluding the charge, it forecast earnings of 14 cents to 16 cents a share.