思考 (sī kǎo) is a verb meaning 'to think' or 'to reflect' — specifically, to engage in careful, deliberate mental activity. The character 思 (sī) means 'to think' or 'to consider', often implying focused attention or contemplation; 考 (kǎo) originally meant 'to examine' or 'to test', and here reinforces the idea of thorough, critical examination. Together, they form a compound that emphasizes active, reflective cognition — not just fleeting thoughts, but purposeful analysis or introspection.

This word is commonly used in academic, professional, and personal contexts: students are encouraged to 思考 deeply about questions; managers ask teams to 思考 solutions before acting; and individuals may 思考 life choices during quiet moments. It carries a formal or serious tone — you wouldn’t use it for casual daydreaming (that’s 想 or 发呆). It frequently appears with modifiers like 认真地 (seriously), 深入地 (deeply), or 独立地 (independently), and often takes an object introduced by 关于 ('about') or a clause marked by whether or not.