X0508 4 2025-11-17 0 0001562088 Duolingo, Inc. DUOL 0001869669 Skaruppa Matthew C/O DUOLINGO, INC. 5900 PENN AVENUE PITTSBURGH PA 15206 0 1 0 0 Chief Financial Officer 1 Class A Common Stock 2025-11-17 4 S 0 2799 177.95 D 40546 D Class A Common Stock 2025-11-18 4 S 0 390 174.0367 D 40156 D Class A Common Stock 2025-11-18 4 S 0 793 175.0015 D 39363 D Class A Common Stock 2025-11-18 4 S 0 880 175.731 D 38483 D Class A Common Stock 2025-11-18 4 S 0 796 176.9087 D 37687 D Class A Common Stock 2025-11-18 4 S 0 200 177.648 D 37487 D Represents shares automatically sold to satisfy tax withholding obligations in connection with the vesting of Restricted Stock Units ("RSUs") and delivery of shares. The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on May 27, 2025. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $173.39 to $174.37, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $174.39 to $175.38, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $175.40 to $176.35, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $176.43 to $177.36, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $177.48 to $177.76, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote. /s/ Stephen Chen, as Attorney-in-Fact for Matthew Skaruppa 2025-11-19