I
noun
BAD : I was sure the old woman was saying lies.
GOOD : I was sure the old woman was telling lies.
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tell a lie (NOT say or speak ): 'I always know when he's telling lies.'
II
verb
BAD : After a while he stopped running and lied down on the ground.
GOOD : After a while he stopped running and lay down on the ground.
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lie (lying, lied, lied) = say something which is not true in an attempt to deceive: 'I wonder why he lied about his age?'
lie (lying, lay, lain) down = be in or get into a horizontal position: 'I lay down on the bed and fell sound asleep.'