F. Dispositional verbs or verbs showing a state of being, such as juéde觉得think/feel, xǐhuan喜欢like, ài爱love, shì是to be, zhīdào知道know, etc., do not take verb-suffix le了.
6.1 Zhāng tàitai jiéhūn yǐqián xìng(x) Wang.
Mrs. Zhang’s family name was Wang before she got married.
6.2 Zuótiān tā juéde(x) bú tài
Yesterday he didn’t feel so well.
6.3 Yǐqián wǒ zhǐ zhīdào(x) tā huì zuò Zhōngguó fàn,
bù zhīdào(x) tā yě huì zuò Yìdàlì
Before I only knew he knew how to cook Chinese food, I didn’t know he also knew how to cook Italian food.
6.4 Yǐqián xué Zhōngwén de xuésheng hěn shǎo(x).
Before there were few students who studied Chinese.
6.5 Wǒ zài dàxué dè shíhou,
tā shì(x) wǒ-de nǚpéngyou. Wǒ fēicháng ài(x) tā.
When I was in college, she was my girlfriend. I loved her very much at that time.