I don't know [right] now is the English equivalent of 'Je sais pas maintenant'. In the word by word translation, the personal pronoun 'je' means 'I'. The adverb '[ne]...pas' means 'not'. The verb 'sais' means '[I] am knowing, do know, know'. The adverb 'maintenant' means 'now'.
"je ne savais pas que tu parlais français"or "j'ignorais que tu savais parler français"
Je le savais in French means "I knew it" in English.
I think that you used to know it is an English equivalent of 'Je pense que tu le savais'.
Je le savais.
"Savais" is the past tense of the French verb "savoir," which means "to know." It can also mean "knew" or "was aware of" depending on the context in which it is used.
"Je savais tout"
"Je savais que tu l'aimerais." "Je savais que vous l'aimeriez." (formal)
I didn't know that you speak French is an English equivalent of 'Je ne savais pas que vous parlez français'. The subject pronoun 'je' means 'I'. The adverb phrase 'ne...pas' means 'not'. The verb 'savais' means '[I] am knowing, do know, know'. The conjunction 'que' means 'that'. The subject pronoun 'vous' means 'you'. The verb 'parlez' means '[you] speak'. The masculine noun 'français' means 'French'. All together, they're pronounced 'zhuhn sah-veh pah kuh voo pahr-leh fraw-seh'.
I didn't know that you speak French is an English equivalent of 'Je ne savais pas que vous parlez en français'. The subject pronoun 'je' means 'I'. The adverb phrase 'ne...pas' means 'not'. The verb 'savais' means '[I] did know'. The conjunction 'que' means 'that'. The subject pronoun 'vous' means 'you all'. The verb 'parlez' means '[you all] speak'. The preposition 'en' means 'in'. The masculine noun 'français' means 'French'. All together, they're pronounced 'zhuhn sah-veh pah kuh voo pahr-lee-eh aw fraw-seh'.
To say "I knew" in French, you would say "Je savais."
savais-tu que ... / est-ce que tu savais que ... saviez-vous que / est-ce que vous saviez
Je savais que vous le feriez