chūntiān 春天 = spring chūtiān nuǎn春天暖=Spring is warm.
xiàtiān 夏天=summer xiàtiān rè 夏天热=Summer is hot.
qiūtiān 秋天=autumn qiūtiān liáng秋天凉=Autumn is cool.
dōngtiān 冬天=winter dōngtiān lěng冬天冷=Winter is cold.
chūtiān nuǎn,xiàtiān rè,qiūtiān liáng,dōngtiān lěng.
春天暖, 夏天热, 秋天凉, 冬天冷。