lapse into: He lapsed into a coma after suffering a brain haemorrhage/hemorrhage. (To pass gradually into a worse state or condition)

lay about:  He laid about his would-be pickpocket with his walking stick. (To beat violently on all sides) 

lay aside:  They may decide to lay aside the building project until the rainy season ends. (To temporarily suspend doing something)

lay aside:  The couple lay/lays aside an amount of money for a summer holiday. (To save for future use)

lay away:  The land has been laid away for a housing project. (To reserve for future use)

lay down:  A call for ceasefire was ignored as both sides refused to lay down their arms. (To stop fighting) 

lay down:  The document lays down clear guidelines on the use of chemicals. (To formulate rule, principle, etc)
lay down:  It is an underground cellar where they lay down wine. (To store (wine) for drinking in the future)

lay in: Residents in this remote region usually lay in sufficient food in case they are cut off by adverse weather conditions. (To store away a supply of something for future use)

lay into:  No one knew why she suddenly laid into him. (To carry out a physical or verbal attack against someone)

lay off:  Mark was laid off after working for the company for twenty years. (To discharge a worker temporarily or permanently)

lay off:  She warned him to lay off excessive alcohol or she would leave him. (To stop doing or using something)

lay on:  They laid on a generous buffet for visitors to their sales promotion. (To provide something such as food, entertainment, etc) 

lay out:  Miniature models of houses and buildings in a new housing estate were laid out for viewing.  (To arrange or spread out something)

lay out:  He has no hesitation in laying out hundreds of dollars on a hotel room for a night. (To spend large amount of money)
lay out:  He was laid out for a few minutes when a ball struck him on the head. (To knock unconscious)

lay over:  He usually lays over when driving on a long journey. (To make a stopover when going on a journey)

lead off:  He led off by thanking those present for joining in the discussion. (To start or begin)

lead on:  How long is he going to let her lead him on before the truth dawns on him? (To deceive)  

lead to:  We took a wrong turn which led us to an old  cemetery. (To join directly to some place)

lead to:  A reward for information led to the capture of the murderer. (To result in something happening)
lead up to: The television documentary recounted the events leading up to the bombing of the airport. (To give an account of something) 

leaf through:  Bob leafed through many magazines while waiting at the clinic. (To turn pages quickly without serious reading)

lean against:  He leaned a ladder against the gutter to reach the roof. (To rest something against something else so that it is supported)

lean on:  In times of difficulty it would be great to have someone to lean on for support. (To derive support from)
lean towards:  Police believe the group is leaning towards terrorism. (To have a tendency)   

leave aside:  Let’s leave that aside as it is not relevant in this discussion. (To not include something)

leave behind:  I have this feeling that I have left something behind, but can’t figure out what it is. (To forget to take something with you)

leave behind:  The deceased left behind a wife and two children. (To have surviving relatives after one’s death)
leave behind:  The tourists left behind a trail of litter. (To go away from a place without taking something along)
leave behind:  The storm has passed, leaving behind a trail of devastation. (To go away and cause something such as damage and destruction to remain)
leave behind:  You will get left behind if you don’t work as hard as the others. (To lag or fall behind)

leave off:  Let’s continue from where we left off. (To stop doing something)

leave out:  This is the first time he is left out of the squad for the World Cup. (To not include someone or something)

let down:  He really let us down by not turning up to show us how to do it. (To disappoint someone) 

let down:  The few of them let the candidate down by switching their support to his opponent.  (To withdraw support)

let in:  Let’s open the windows and let the air in. (To allow something to enter)

let in:  She believed the house was haunted as the bedroom door once opened by itself and let her in. (To allow someone to enter)
let in:  He’s beginning to realize how much trouble he is letting himself in by borrowing heavily from different sources. (To place oneself in a difficult situation)
let in on:  She’s prepared to let me in on her secret recipe if I promised not to tell other people. (To trust someone) 

let into:  They only let certain individuals into the building. (To allow someone to enter)  

let off:  If you pluck my apples again, I’ll not let you off. (To not punish someone)

let off:  Someone tied a string of firecrackers to a dog’s tail and let it off. (To make something explode)

let on:  He made her promise not to let on that he did it. (To reveal something) 

let out:  It usually barks when it wants to be let out. (To allow someone or something to leave)

let out:  When she heard the news, she let out a sigh of relief. (To utter a sound)
let out:  She’s letting some of her clothes out as she has put on weight. (To make an item of clothing looser)

let up:  It looks like the rain is not going to let up, so what shall we do? (To stop or abate)

let up:  The rescuers will not let up in their effort to find the missing victims. (To become less determined)

level against:  They have yet to prove the charges relating to embezzlement leveled against him. (To direct accusation at someone)

level at:  All he can ever do is level criticism at others for their mistakes. (To aim something such as criticism, accusation, weapon, etc at someone)
level off:  Prices of houses in the area have leveled off after recent hike. (To not fluctuate)
level out:  After reaching the height of 20,000 feet, the plane leveled out. (To move horizontally)
level with:  The candidate’s aides will level with him about what the voters are saying about him. (To speak frankly)