In fiction, there are no rules about sentence length, and sentences can be as long or as short as you decide. However, lots of long and rambling sentences can be off-putting, meaning your reader could lose interest. Cramming too much information into sentences may also slow the reader down and make the plot difficult to follow.

Long sentences and too much description

If your book is written using mainly long sentences, some of your readers may feel alienated. Many of us have a passion for a particular genre, such as crime and thrillers and will have certain expectations. Readers know that crime and thrillers will usually have plot twists, several high-tension scenes and move at a fast pace. If we want a bit of escapism after a tough day at work or when we are on holiday, a book filled with rambling, complex sentences and poetic prose might not hold our attention.  But this sort of writing has a place in other genres, for example literary fiction.

There is often a temptation to give too much information to readers. Especially if the book is an author’s first.  Some description is essential so the reader can picture a scene, but readers can usually fill in the missing bits. It’s important to remember that the information given must move the story forward, rather than provide unimportant detail for the sake of it and to pad out the story.

Vary sentence length

Varying the length of sentences will add rhythm and keep the reader interested.

The made-up passage below is very repetitive and tedious to read. Although this paragraph includes short sentences, most have five words and they all read with the same rhythm. There’s no excitement or tension.

Clare looked at him suspiciously. She thought he was trouble. She wondered what to do next. She picked up her phone. She called Tim’s number. Tim didn’t answer the call.  The man moved towards her.

Consider the rewrite below.

Clare narrowed her eyes. He looked like trouble. Big trouble. Crumbs, what should she do next? Ring someone? But who? Her heart was pounding. Think, think.  Tim! Of course. Thank goodness for his text yesterday. Cursing, she stabbed furiously at the phone. Come on, come on, pick up. Tim’s voicemail cut in. Now what? The man edged closer.  She swallowed and stepped back.

The rewritten example is more immersive for the reader. The sentences are still short, but some snappy fragments have been introduced along with some single words. Adding in free indirect style and action beats creates more tension and intrigue.

The extract below shows use of different sentence lengths and structures in a published book.

Standing up, I walk to the windows. The pavements and roads are completely white with snow. And almost entirely empty, except for one woman in black, passing my door, down there. Street level. She is pulling little kids, she has her back to me. I can’t see her face. Clearly, she is dragging the children home, hurrying them along, before this thick, whirling snow gets too much. I feel sorry for her. Something in her stance evokes pity. Quite fierce sympathy: as if she could have been me. And then she has gone. Disappeared. A gust of snow? She turned a corner.

The Assistant by S. K. Tremayne, Chapter 3, audiobook

Use different sentence structures

Using the same structure throughout your book will certainly become boring for your reader. Many new authors like to use participles at the beginning of sentences as shown in the made-up example below.

Glinting in the sun, something in the distance caught Clare’s eye. Bending down, she looked at the cheese knife. Picking it up, she examined it more closely. If she wasn’t mistaken there was blood smeared along the blade. Dropping it back on the floor, she looked around her. Getting out her phone, she dialled 999.

The repetition of this type of sentence can be irritating to read. It’s best done in moderation alongside a variety of other sentence structures. The edited version is much improved.

Something glinted on the path ahead. Clare shielded her eyes. What was it? She bent down and peered at the object. It was a cheese knife. She frowned and picked it up. The blade was smeared with something sticky and deep red. Christ, was it blood? Why the hell had she picked it up? She dropped it as if it was red hot and looked around. Thank God no one was about. Hands shaking, she pressed 999.

Short sentences and sentence fragments

You might be thinking that sentences need a subject and verb otherwise they are not complete. Technically this is correct. But this is fiction and sentence fragments are acceptable as are single-word sentences.

Sentence length can alter the mood and tone of a scene dramatically. In crime and thriller fiction the reader expects lots of tension, which means that the story moves at a faster pace.

Imagine a character sitting peacefully on a riverbank alone with their thoughts, watching the flow of the river and listening to birdsong. We might expect to see long and languid sentences to match the mood of the scene. If the character saw a body floating down the river, we could expect shorter sentences and ungrammatical fragments to show the urgency and panic that would ensue.

In scenes of high tension, short, snappy sentences or sentence fragments convey the mood and drama. They also affect our emotions. When I am reading high-tension scenes, I am glued to the page, holding my breath to see what happens next. I feel like I am there with the characters and experiencing what they are experiencing.

Short and concise sentences and sentence fragments are an excellent way of conveying different moods and increasing tension. They are also effective at showing the viewpoint character’s state of mind. In a high-tension situation, we are all likely to panic and be unable to focus on thinking clearly or speaking coherently. For example, fear and panic can be shown using fractured or concise phrases as the made-up example below shows.

He was closing in. Which way should she go? Left? No. Too exposed. Right? Busy road.  Oh God. What to do. She darted into the undergrowth.

Expletives can also come in very useful when the stakes are high! In high-drama situations even the most clean-mouthed among us will probably be thinking, if not saying, some sort of obscenity.

Passages of short, ungrammatical sentences and sentence fragments are best used in short bursts and kept for moments of high tension when the pace needs to be faster. Filling the book with long passages written in this way would become tedious to read and the story would lose its impact.

Free indirect style

Using free indirect style means the reader can get right into the characters’ thoughts and emotions. There is no narrative distance between the reader and the character. As these are thoughts, it’s acceptable for them to be disjointed. Especially in nerve-wracking situations. The reader gets to experience the character’s natural thought process without the clutter of dialogue tags, quotation marks or italics. In the extract below, we are right there in Emily’s mind and feel how she must be feeling as she hides in a ditch.

Where is it? Shit. Shit, shit, shit. I can barely keep the panic at bay now, and I want to curl up in a ball at the bottom of the ditch and wail.

Hide by Nell Pattison, Chapter 28, BorrowBox

Read your book aloud

If you read your work aloud, you’ll be amazed at how over-long sentences and repetition jump out at you. Reading aloud is also useful for picking up typos and spelling errors.

Long sentences in dialogue

You may have a character that is prone to being verbose, in which case this could be shown in their dialogue by using long sentences. But do this sparingly otherwise it will turn into a monologue and your reader will lose interest. You could use short sentences and single words for a character who speaks abruptly. They could just snap one word demands or answers in their dialogue.

Final thoughts

• Use a variety of sentence lengths and structures to keep your reader interested.
• Short and snappy fragments, very short sentences and single words are great to use in moments of high tension.
• Use free indirect style to show a character’s thoughts under pressure and in tense situations.
• Read your story aloud to help gauge whether your sentences are too long or repetitive.
• Use dialogue to show the speech of a verbose or abrupt character, but don’t overdo it.

References

Hide, Nell Pattison, Avon, 2021.

The Assistant, S.K. Tremayne, HarperCollins, 2019.