DUOL · Duolingo, Inc.

Represents an award of fully vested restricted stock units ("RSUs") in lieu of cash retainers pursuant to reporting person's election under the Issuer's Amended and Restated Non-Employee Director Compensation Program (the "Plan"). Each RSU represents the right to receive one share of the Issuer's Class A Common Stock and will be settled either on a date selected by the reporting person pursuant to the Plan or as otherwise provided under the Plan.

Represents an award of fully vested restricted stock units ("RSUs") in lieu of cash retainers pursuant to reporting person's election under the Issuer's Amended and Restated Non-Employee Director Compensation Program (the "Plan"). Each RSU represents the right to receive one share of the Issuer's Class A Common Stock and will be settled either on a date selected by the reporting person pursuant to the Plan or as otherwise provided under the Plan.

Represents an award of fully vested restricted stock units ("RSUs") in lieu of cash retainers pursuant to reporting person's election under the Issuer's Amended and Restated Non-Employee Director Compensation Program (the "Plan"). Each RSU represents the right to receive one share of the Issuer's Class A Common Stock and will be settled either on a date selected by the reporting person pursuant to the Plan or as otherwise provided under the Plan.

Represents an award of fully vested restricted stock units ("RSUs") in lieu of cash retainers pursuant to reporting person's election under the Issuer's Amended and Restated Non-Employee Director Compensation Program (the "Plan"). Each RSU represents the right to receive one share of the Issuer's Class A Common Stock and will be settled either on a date selected by the reporting person pursuant to the Plan or as otherwise provided under the Plan.

The options are fully vested and exercisable.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of the Issuer's Class A Common Stock for each RSU upon vesting. 100% of the RSUs vest on the earlier of (i) the first anniversary of the grant date or (ii) the date of the next annual meeting of the Issuer's stockholders following the grant date, subject to the Reporting Person's continued service to the Issuer.

The performance-based condition will be satisfied upon the Issuer's Class A common stock achieving certain stock price hurdles over a period of ten years. Vested PSUs will be settled by the issuance of the underlying Class B Common Stock on the first anniversary of vesting, subject to acceleration upon a termination of employment or a change in control of the Issuer.

Each Performance-Based Restricted Stock Unit ("PSU") represents a contingent right to receive one share of the Issuer's Class B Common Stock upon vesting. The PSUs vest upon the satisfaction of both a service-based condition and a performance-based condition. The service-based condition is satisfied as to 25% of the PSUs on each anniversary of the completion of the Issuer's initial public offering of Class A common stock based on the Reporting Person's continuous service as CEO to the Issuer through the applicable vesting dates, subject to acceleration upon a cessation of service as CEO as a result of death or permanent disability.

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

Each Performance-Based Restricted Stock Unit ("PSU") represents a contingent right to receive one share of the Issuer's Class B Common Stock upon vesting. The PSUs vest upon the satisfaction of both a service-based condition and a performance-based condition. The service-based condition is satisfied as to 25% of the PSUs on each anniversary of the completion of the Issuer's initial public offering of Class A common stock based on the Reporting Person's continuous service as CTO to the Issuer through the applicable vesting dates, subject to acceleration upon a cessation of service as CTO as a result of death or permanent disability.

The performance-based condition will be satisfied upon the Issuer's Class A common stock achieving certain stock price hurdles over a period of ten years. Vested PSUs will be settled by the issuance of the underlying Class B Common Stock on the first anniversary of vesting, subject to acceleration upon a termination of employment or a change in control of the Issuer.

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on September 15, 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 $112.71 to $113.60, 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 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 $113.82 to $114.66, 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 sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on September 15, 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 $113.85 to $114.64, 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 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 $112.82 to $113.68, 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.

Represents shares automatically sold to satisfy tax withholding obligations in connection with the vesting of RSUs and delivery of shares.

Constitute Restricted Stock Units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Issuer's Class A Common Stock for each RSU upon vesting. 1/16th of the RSUs shall vest on each quarterly anniversary of May 15, 2026.

Constitute Restricted Stock Units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Issuer's Class A Common Stock for each RSU upon vesting. 1/16th of the RSUs shall vest on each quarterly anniversary of May 15, 2026.

Constitute Restricted Stock Units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Issuer's Class A Common Stock for each RSU upon vesting. 1/16th of the RSUs shall vest on each quarterly anniversary of May 15, 2026.

Represents shares automatically sold to satisfy tax withholding obligations in connection with the vesting of RSUs and delivery of shares.

Represents shares automatically sold to satisfy tax withholding obligations in connection with the vesting of Restricted Stock Units ("RSUs") and delivery of shares.

The shares subject to the option are fully vested and exercisable.

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

Constitutes restricted stock units ("RSUs") which represents a contingent right to receive one (1) share of the Issuer's Class A Common Stock upon vesting. The RSUs vest over four years, with 25% of the award vesting on February 15, 2027, and the remainder of the award vesting in equal quarterly installments thereafter, subject to the Reporting Person's continued service through each vesting date.

The shares subject to the option are fully vested and exercisable.

The shares subject to the option are fully vested and exercisable.

The shares subject to the option are fully vested and exercisable.

The price reported in Column 4 is a weighted average purchase price calculated by the broker executing the purchases. These shares were purchased in multiple transactions at prices ranging from $99.07 to $99.96, 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 purchased at each respective price within the range set forth in this footnote.

The shares subject to the option are fully vested and exercisable.

The shares subject to the option are fully vested and exercisable.

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 $111.83 to $112.80, 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 sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on November 14, 2024.

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 $112.87 to $113.77, 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 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 $111.83 to $112.79, 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 sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on November 14, 2024.

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 $114.92 to $115.57, 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.