For parallel construction, it helps to be able to identify the parts of a speech, phrases, and clauses in a sentence. If you can’t do this, then you need a very good ear for it.

Parallel construction isn’t really a grammatical rule. It represents a style choice that has become ingrained into grammar because it represents writing that is easier to read and easier to understand. In fact, the previous sentence provides an example of parallel construction: easier to read and easier to understand.

The highlighted phrase represents parallel construction because it is constructed in almost the same manner except for the last word. Here are some popular examples of parallel construction.

I came, I saw, I conquered.

Julius Caesar

My fellow Americans, ask not what your country can do for you, ask what you can do for your country.

John F Kennedy

One small step for man, one giant leap for mankind.

Neil Armstrong

It is rather for us to be here dedicated to the great task remaining before us–that from these honored dead we take increased devotion to that cause for which they gave the last full measure of devotion–that we here highly resolve that these dead shall not have died in vain–that this nation, under God, shall have a new birth of freedom–and that government of the people, by the people, and for the people, shall not perish from the earth.

Abraham Lincoln

We are not now that strength which in old days
Moved heaven and earth, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To seek, to strive, to find, and not to yield.

Alfred Lord Tennyson

The passages above provide examples of parallel construction. Parallel construction merely refers to the fact that when we have lists whether for describing or doing, the list items should be constructed in a similar fashion. In order to understand this concept better, let’s look at some sentences that are not parallel in their construction and then fix them.

The house was full of old newspapers, moldy magazines, and a collection of used napkins.

So, this is what we have:
old newspapers (one adjective + noun)
moldy magazines (one adjective + noun)
a collection of used napkins (noun + prepositional phrase)

Therefore, we need to fix the last one: “a collection of used napkins.” We can change to, “used napkins.”

The house was full of old newspapers, moldy magazines, and used napkins.

Let’s try some more.

Young people use their phones to text their friends, social media posts, and find someplace to eat.

So this is what we have
text their friends (verb + modifiers)
social media posts (adjectives + noun)
find someplace to eat (verb + modifiers)

Now we need to fix the middle phrase: “social media posts.” We need to use a verb to start. And we can turn “posts” a plural noun into the verb “post.” So, our phrase should be “post to social media.”

Young people use their phones to text their friends, post to social media, and find someplace to eat.

Let’s look at another example.

Cursing and talking so loudly it sounded like yelling, Charlie gave the driver next to him a piece of his mind.

So, this time our structure is at the beginning of the sentence in the form of a participle phrase, “Cursing and talking so loudly that it sounded like yelling,” which is modifying the subject of the sentence: Charlie.
So, this is what we have

Cursing (noun)
Talking so loudly it sounded like yelling (noun + modifiers).

NOTE: Cursing and talking may seem like verbs: things you do. But in this case, we are talking about the act of cursing and the act of talking, which then makes them nouns. We use them as nouns when we say things like, “The cursing and talking at the meeting were getting out of hand.”

To fix this we only need to get rid of the modifiers after talking. And it doesn’t “sound” like yelling, it is yelling. So, let’s just cut to the chase.

Cursing and yelling, Charlie gave the driver next to him a piece of his mind.

Now remember, parallel construction means that list items should be constructed in a similar manner.