Question

I speak the truth. I am not afraid of it.
Combine.

Answer 1

I speak truth and not afraid of it

Answer 2

I am not afraid of speaking the truth.

Here the two sentences are combined by using the participle 'speaking'

Combining two or more simple sentences into one new sentence is known as Sentence synthesis. The new sentence may be a simple sentence, a complex sentence or a compound sentence. Combining two sentences can be done

i)  By using infinitives

   I have to support my family. I want to find a job.

   I want to find a job to support my family.

ii) By using a noun or phrase in apposition

   This is my sister. Her name is Mira.  

   This is my sister, Mira.

iii)By using a participle

    I saw the fox. It was chasing a rabbit.

   I saw the fox chasing a rabbit.