Liquid crystal composition and liquid crystal display device

A liquid crystal composition that has positive dielectric anisotropy, and contains at least one compound selected from the group of compounds represented by formula (1) as a first component, a compound represented by formula (2) as a second component, at least one polar compound as a first additive and at least one polymerizable compound as a second additive:

• wherein, in formula (1), R1a is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons;
• ring Q and ring S are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl;
• Z1a and Z2a are independently a single bond, —CH2CH2—, —CH═CH—, —CH2O—, —OCH2—, —COO—, —OCO—, —CF2O— or —OCF2—;
• X1a and X2a are independently hydrogen or fluorine;
• Y1a is fluorine, chlorine, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine, alkoxy having 1 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine, or alkenyloxy having 2 to 12 carbons in which at least one hydrogen is replaced by fluorine or chlorine;
• q is 1, 2, 3 or 4;
• s is 0, 1, 2 or 3;
• and a sum of q and s is 4 or less.