Similar letters but said differently.

THOUGH   TOUGH    THOROUGH    THOUGHT   THROUGH

Though   /ðəʊ/      although, in spite of, despite the fact that.

Maria went on holiday, though she didn’t really have the money.
Paul did not get approved for the new job, though he had all the necessary experience.
Even though it was raining, we enjoyed the car ride in the countryside.

Tough    /tʌf/       hard, hard surface, difficult task, severe situation

That was a tough exam, but I’m glad i passed.
The marathon was tough, but everyone crossed the line.
The skateboard is made of a new tough composite material.

Thorough   /ˈθʌr.ə/  
extremely accurate, very detailed, in-depth, carried out completely and carefully

This dirty car needs a thorough cleaning.
The police made a thorough investigation of the robbery.
The research about opening a new restaurant in London has been thorough and accurate.

Thought   /θɔːt/   
this is the past tense from the verb “to think” , an idea

I thought it would be good to exercise more.
I haven’t thought about changing my job.
What are your thoughts on the idea of free bus passes for the elderly.

Through   /θruː/  
movement from one side to the other, passage into and out of

The crowd was so thick, i couldn’t walk through it.
There is a train that runs through the city.
We drive our car through the tunnel.
All through her life, Sarah always helped those in need.