Particles are small words that are used in English sentences to show relationships between words or to add emphasis. In this article, we will discuss the correct usage of particles in different contexts.

1. Go [ ] your work before you hand it in. Correct answer: through Explanation: The particle "through" is used to indicate completing a task or process.
2. What's going [ ] here? Correct answer: on Explanation: The particle "on" is used to indicate a current situation or activity.
3. How much longer will this hot weather go [ ] for? Correct answer: on Explanation: The particle "on" is used to indicate the continuation of a situation or activity.
4. He's very optimistic considering all difficulties he's had to go [ ]. Correct answer: through Explanation: The particle "through" is used to indicate overcoming obstacles or challenges.
5. He didn’t like the party so he decided to go [ ]. Correct answer: away Explanation: The particle "away" is used to indicate moving from a place or situation.

In conclusion, particles play an important role in English sentences by providing clarity and adding nuance to the meaning of the sentence. By understanding the correct usage of particles, you can improve your English language skills and communicate more effectively.