Question

My tooth was aching so I went to the dentist?

Answer 1

In this sentence, the word so is used to join two independent clauses: 

1. \( \text{Clause 1: My tooth was aching} \)
2. \( \text{Clause 2: I went to the dentist} \)

The word so connects these two clauses and shows a cause-and-effect relationship. In grammar, such connecting words are known as Conjunctions.

A conjunction is defined as: \[ \text{Conjunction} = \text{a word that joins two words, phrases, or clauses} \]

Here: \[ \text{My tooth was aching} \; + \; \text{so} \; + \; \text{I went to the dentist} \] The conjunction "so" combines two complete ideas into one meaningful sentence.

Conclusion:

Therefore, the word so in this sentence functions as a Conjunction.