To sparkle is to give off small flashes of light. Figuratively, a person sparkles when they are very lively and funny.
Ex: Orlando's suit is made from a strange, shiny fabric. It really sparkles when he goes into the sunlight. It's strange at first but quite pretty.
Ex: Lisa is a bit shy at first, but after a couple of glasses of wine she really begins to sparkle. She can tell great jokes, and becomes the life of the party.
When you begin something, especially a conversation, debate or friendship, you can say you spark it up.
Ex: When Callie sat down on the train, she immediately tried to spark up a conversation with the other passengers on the train. She's always been a friendly person like that.
Ex: When the two boys met they sparked up a friendship right away. In fact they've been best friends ever since that day.
Like twinkle, flicker means to give off an irregular light that varies from bright to faint. But whereas twinkle is often positive or poetic, flickering implies that the light might soon go out—like a candle in the wind or a light bulb that is too old.
Ex: Vanessa became quite worried when she went into the kitchen and saw the lights begin to flicker. It seemed the apartment building might be having electrical problems again.
Ex: The Christmas lights began to flicker just after we turned them on. I think a few of the lights are loose and they cause the whole string to blink off from time to time.
The car signals that blink or turn on and off are sometimes called the flickers. They can also be called blinkers. When a light like a candle flickers until it finally goes out we say it flickered out.
Ex: I know you aren't supposed to park here, but if you just put your blinkers on and run into the bank really fast, I think it'll be ok. The police will see your lights and realize you aren't parking there for a long time.
Ex: After the candle had been burning for a few hours, it finally began to flicker and fade until it finally flickered out. Then the room was dark.