The Basics

And, But, and Or are conjunctions that are used to connect parts of a sentence together.

The Chart

Chart One

to comma not to comma
and X
but X
or X X

Chart Two

Conjunction Symbol
OR +/-

The Logical Structure

There is a logic to how and, but, and or are used. Specifically, and is equivalent to plus (+) or in addition to; but is equivalent to minus (-) or to take away from or to not include; and or is equivalent to all possible or not all possible.

How this looks


The conjunction AND states that both nouns or clauses on both sides of AND are required for all parts to be true.

Therefore, for the following:

Jack and Jill went up a hill to fetch a pail of water.

to be true, both Jack and Jill had to climb the hill. It also tells us that both Jack and Jill went up the hill. It’s to combine.

See also:

Bob and Boris both ate some porridge and then both fell asleep.

In Series

Both AND, BUT, and OR can be used in series. A series is any string of conditions that may or may not be true. When used in a series, such as:

Apples, oranges, pears, and lemons

Apples, oranges, pears, or lemons

Apples oranges pears, but (and not) lemons

Dominant and Subordinate

AND can also be used to combine two clauses or two incomplete sentences, forming a complete sentence. In this way, there will always be a dominant side and a subordinate side. The dominant side is the one that possess or is in possession of the subject. While the subordinate side requires the dominant for it’s subject.

In the case of a dominant-subordinate relationship, then a comma is necessary between the dominant clause before the and and subordinate clause.


Belongs to the left of the AND and exists before the comma.


Belongs to the right of the AND and exists after the comma.