Spin a yarn
To tell a tale or story.I like my new neighbor because he always likes to spin a yarn.
Spill the beans
To tell a secret.My friend promised not to spill the beans about my plans to get married.
Spick-and-span spic-and-span
Very clean, very neat.The house was spick-and-span when we returned from our holiday.
Spring for (something)
To buy something, to pay for something.I will spring for a new camera before I go on my vacation.
Splurge on (something)
To spend a lot of money on something.The boy splurged on a beautiful present for his girlfriend.
Split up
To end a relationship.The girl and her boyfriend decided to split up after being together for seven years.
Spell trouble
To signify future trouble, to mean trouble.The problems that we are having with our furnace spell trouble for the coming cold season.
Spell (something) out spell out (something)
To explain something in very simple words, to explain something very clearly.I spelled out the conditions for renting the house very clearly.
Speak with a forked tongue
To tell lies.The man speaks with a forked tongue and nobody trusts him.
Speak up for (someone or something)
To speak in favor of someone or something.The politician is always willing to speak up for the poorest people in the city.