<SEC-DOCUMENT>0001628280-21-014595.txt : 20210727
<SEC-HEADER>0001628280-21-014595.hdr.sgml : 20210727
<ACCEPTANCE-DATETIME>20210727210910
ACCESSION NUMBER:		0001628280-21-014595
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210727
FILED AS OF DATE:		20210727
DATE AS OF CHANGE:		20210727

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Union Square Ventures 2012 Fund, L.P.
		CENTRAL INDEX KEY:			0001532179
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40653
		FILM NUMBER:		211119568

	BUSINESS ADDRESS:	
		STREET 1:		915 BROADWAY
		STREET 2:		19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10010
		BUSINESS PHONE:		212-994-7880

	MAIL ADDRESS:	
		STREET 1:		915 BROADWAY
		STREET 2:		19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10010

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			USV Investors 2012 Fund, L.P.
		CENTRAL INDEX KEY:			0001537452
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40653
		FILM NUMBER:		211119567

	BUSINESS ADDRESS:	
		STREET 1:		915 BROADWAY, 19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10010
		BUSINESS PHONE:		212-994-7800

	MAIL ADDRESS:	
		STREET 1:		915 BROADWAY, 19TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10010

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Duolingo, Inc.
		CENTRAL INDEX KEY:			0001562088
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				453055872
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5900 PENN AVE, SECOND FLOOR
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15206
		BUSINESS PHONE:		(412) 347-6116

	MAIL ADDRESS:	
		STREET 1:		5900 PENN AVE, SECOND FLOOR
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15206
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_162743451376294.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-07-27</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001562088</issuerCik>
        <issuerName>Duolingo, Inc.</issuerName>
        <issuerTradingSymbol>DUOL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001532179</rptOwnerCik>
            <rptOwnerName>Union Square Ventures 2012 Fund, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNION SQUARE VENTURES</rptOwnerStreet1>
            <rptOwnerStreet2>915 BROADWAY, 19TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001537452</rptOwnerCik>
            <rptOwnerName>USV Investors 2012 Fund, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O UNION SQUARE VENTURES</rptOwnerStreet1>
            <rptOwnerStreet2>915 BROADWAY, 19TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2394100.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series A Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>92618.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1166113.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>45113.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of Series A Preferred Stock of the Issuer will automatically convert on a 1-for-1 basis into Class B Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.</footnote>
        <footnote id="F2">Union Square 2012 GP, L.L.C. (&quot;Union Square 2012&quot; and together with affiliated entities, &quot;Union Square Ventures&quot;) is the general partner of USV 2012 Fund and USV Investors 2012 Fund, and has sole voting and investment power with regard to the shares held by USV 2012 Fund and USV Investors 2012 Fund. Fred Wilson, Brad Burnham, Albert Wenger, John Buttrick, and Andy Weissman are partners at Union Square Ventures and, therefore, may be deemed to have shared voting and investment power with regard to the shares held directly by USV 2012 Fund and USV Investors 2012 Fund. Each of these individuals disclaims beneficial ownership of these shares except to the extent of their pecuniary interest therein, if any.</footnote>
        <footnote id="F3">Shares held by Union Square Ventures 2012 Fund, L.P. (&quot;USV 2012 Fund&quot;).</footnote>
        <footnote id="F4">Shares held by USV Investors 2012 Fund, L.P. (&quot;USV Investors 2012 Fund&quot;).</footnote>
        <footnote id="F5">The shares of Series B Preferred Stock of the Issuer will automatically convert on a 1-for-1 basis into Class B Common Stock of the Issuer immediately prior to the closing of the Issuer's initial public offering.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Union Square Ventures 2012 Fund, L.P.
By: Union Square 2012 GP, L.L.C., its General Partner
By: /s/ Brad Burnham, its Managing Member</signatureName>
        <signatureDate>2021-07-27</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>USV Investors 2012 Fund, L.P.
By: Union Square 2012 GP, L.L.C., its General Partner
By: /s/ Brad Burnham, its Managing Member</signatureName>
        <signatureDate>2021-07-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
