You need to buy a grammar book. That's what they are for.

say means to speak tell means to give information or facts to someone So. say doent need an object, but tell needs an object. he said i won a prize. he said that he won a prize. he told me he won a prize. he said nothing. he said goodbye. he told( us )the truth. the clock tells( us) the time. you shouldn't tell lies. i hope this helps. he told his friends that he had a bad dream last night.

We normally use an indirect object after 'tell' but not after 'say': 'Anne told ME she's fed up.' NOT 'Anne told she's fed up.' 'Anne said she's fed up.' NOT 'Anne said me she's fed up.' We can use 'tell' + indirect object + about: 'Anne told us about her new boyfriend.' But we can use 'tell' without an indirect object in these expressions: Paul told (us) a very funny story/joke. You must tell (me) the truth. You mustn't tell (people) lies. The pupils have learnt to tell the time.