# Using co-ordinating conjunctions

My question is about the following sentence. Punctuation omitted.

If the man comes back and I am home I will arrest him

In the sentence there is one dependent subordinate clause and two independant clauses.

I have two questions.

1. How would this sentence be punctuated, and coördinating conjunctions are said to separate like things. Subjects, verbs, and independent clauses as examples.

2. Why does it sound perfectly normal that in the example a subordinate clause is being separated by an independent clause using a coördinating conjunction?

• There's only one subordinate clause, although it has two parts. The "if" clause contains both "the man comes back" and "I am home". Dec 12, 2014 at 15:46
• If the two conditions previously stated hold, I will arrest him. Dec 12, 2014 at 15:57
• Thank you for hyphenating co-ordinating. I applaud you sir. Dec 13, 2014 at 0:24

First, I cannot agree that there are two independent clauses here. There is one simple independent clause: "I will arrest him". There is a compound subordinate clause: "the man comes back and I am home". The coordinating conjunction "and" combines two complete clauses. The subordinating conjunction "if" relates the entire compound to the independent clause.

When a coordinating conjunction connects two independent clauses, a comma makes sense. In this case, the clauses are not independent.

When a sentence begins with a long introductory structure, a comma at the end of that structure makes sense. In this case, the compound subordinate clause is a long introductory structure.

Given these guidelines, it is appropriate to punctuate the sentence as follows:

If the man comes back and I am home, I will arrest him.

The reason that the "and" sounds natural is that it does connect two like things. Each of those things is a complete subordinate clause. The sentence also sounds natural if each of the subordinate clauses has its own subordinating conjunction:

If the man comes back and if I am at home, I will arrest him.

If the middle clause were independent, the meaning of the sentence would be completely different:

If the man comes back, I am at home, and I will arrest him.