Which version of this sentence with a linking adverb is grammatically acceptable?

I am unsure if the word "therefore" is called a linking adverb.

I have the following sentences. Which version is grammatically acceptable?

• My preference, therefore, is to travel by train

• My preference is, therefore, to travel by train.

Should "therefore" be separated by a comma?

(I want to use "therefore" in the middle of the sentence. I know it can be used in the beginning and end of a sentence.)

Solution 1:

Both sentences are technically grammatically correct. The first sentence using "therefore" before the copula flows better because the verb phrase remains more intact.

Solution 2:

I think it does flow a little better with the verb after the therefore.

My preference, therefore, is your first option.

Solution 3:

I think they are both grammatical. Be sure that this sentence follows one that gives the reason for the preference to travel by train. And, yes, commas should be on either side of therefore.

You are correct that therefore is a linking adverb. It is more specifically a result/inference linking adverbial.

http://www.tesl.iastate.edu/510/F04/comp/handouts/cohesion.pdf

Excerpt from that link: Result/inference linking adverbials demonstrate to readers that the following textual element is the result or consequence of the previous information. A few examples of result/inference linking adverbials are

• consequently
• thus
• as a result
• hence
• so
• therefore