What Part of Speech Is “By”? Definition, Uses, and Examples

‘By’ doesn’t necessarily belong to a particular part of speech. It depends on how you utilize it within a sentence, and it can belong to more than one. You never know; it can function as a preposition, an adverb, or an adjective. 

Therefore, it can be a little tricky to understand how to place the word ‘by’ correctly in a sentence. Hence, this guide helps you understand what exactly “by” is doing every time you see it. 

What Part of Speech Is ‘By’? A Quick Answer

The word ‘by’ can belong to any of the parts of speech, like prepositions, adverbs, or adjectives, depending on the sentence you write.  This word is often used as a preposition, but it can also be a noun very rarely, mainly in the context of sports. 

Part of Speech	Explanation	Example
By as a Preposition	Here, ‘by’ joins a noun or pronoun with the rest of the sentence.	She completed the presentation by Thursday.
By as an adverb	In this case, ‘by’ generally indicates direction or proximity. It stands alone, without an object.	Today, I saw John walk by.
By as a noun	Here, ‘by’ can have different meanings, one being something of lesser importance, or something that is being passed over. Often spelled ‘bye’	The team has a bye this weekend.

Remember, one rule about ‘by’ is that if it has a noun or pronoun after it that it logically governs (has a relationship with), then it’s a preposition. If it doesn’t have a noun after it, then it’s an adverb.  

‘By’ as a Preposition

‘By’ is mostly used as a preposition in a sentence. It has the job of connecting a noun, pronoun, or a noun phrase to the remaining sentence. Here, ‘by’ usually indicates some sort of relationship to the verb or verb phrase in the sentence. 

1. Many different kinds of relationships can be expressed by the preposition ‘by’, the most common of which are listed below:

2. Used to explain who or what performed the action. “This building was designed by a group of local architects.”

3. Used to explain the means and method of the action in the sentence. “They went across the state by bus.”

4. Used to highlight the proximity or location. “The indoor plants were kept by the window all summer.”

5. Highlighting a deadline or a time limit when an action should be completed. “Please try to submit the assignment by Friday.”

6. Used to highlight the conformity or standard. “This dress was designed by hand, not just machines.”

7. Highlighting a mathematical or proportional relationship. “The recent sales increased by 15%.”

Look at the pattern in all the examples. Every ‘by’ here is followed by a noun or pronoun. That’s the key to identifying prepositions. 

‘By’ as an Adverb

“By” is not always followed by a noun or pronoun. It can also provide some types of adverbial information. You may recall from our adverbs guide that they share information like time, place, manner, degree, or reason of the action. In this case, ‘by’ usually modifies a verb, indicating a location or time, not introducing an object itself. 

For example:

• “The bus behind us sped by without slowing down.” In this context, it’s clear that “by” is an adverb modifying the verb “sped”, showing the direction of the car’s movement, rather than being a preposition introducing an object. 

• “He stopped by on his way back from the gym.” Here, ‘by’ modifies the verb ‘stopped’, providing information about the manner of stopping.

Quick tip: If you skip the word ‘by’ and find the sentence still making basic sense, then it is a sign that ‘by’ is an adverb, rather than a preposition. 

‘By’ as a Noun

‘By’ as a noun is rare, but it does happen, and it can be confusing when it does. The word ‘by’ is spelled as ‘bye’ in this context, which means something that’s been set aside, or passed over, or is of secondary importance to something else. The use of ‘by’ as a noun mostly happens in sports, specifically in scheduling. 

For example:

• “The team was happy to have a bye week following consecutive games.”

• In a tournament setting, bye can also mean to advance to the next round automatically because there’s no one to play. 

For example:

• “She got a bye in the second round as the best player.”

• This word is also sometimes used in very old or very formal writing outside of sports to refer to something incidental or passing. Note that whenever bye is being used as the subject, rather than to modify or link ideas (as it usually would be in English), it is being used as a noun. 

Common Phrases and Idioms That Use ‘By’

In English, the word ‘by’ has become part of numerous common phrases. Understanding these phrases is beneficial for you to prevent overcomplicating the grammar behind them, as many have an idiomatic meaning to them. These are some common phrases with the word ‘by’:

Common Phrase	Meaning	Example
By and large	Means ‘overall’ or ‘generally speaking’	By and large, the latest proposal was positively received.
By heart	Completely memorized	I know that song by heart.
By the book	Done officially and properly in accordance with a system or set of rules	The chef followed the recipe by the book.
By the way	Introducing a digression or a different subject	By the way, have you checked on the exam results?
By all means	Definitely or certainly (used to give permission)	By all means, take a day off tomorrow; you need it.
By far	To a much greater extent or degree than others	This is by far the best biscuits I have ever tasted. .

Important: ‘By’ is used with the following words to create meaningful phrasal constructions. It is best to remember the expressions as a whole rather than analyzing the meaning of each word that makes up the phrase. 

‘By’ vs. Similar Prepositions: Near, Until, and Beside

It is common for learners to confuse ‘by’ with certain prepositions that share the same meaning with each one but are not interchangeable. The difference between these prepositions and ‘by’ is highlighted below:

By vs. Near: both of these words indicate proximity to something. The main difference is that ‘by’ implies direct contact and closeness, and near suggests a distance, however small. 

For example: 

• The table is by the window (right next to the window). 
• The table is near the window (somewhere close to it). 

By vs. Until: Though both refer to time, they differ, as ‘by’ is used for marking deadlines while ‘until’ indicates duration. 

For example:

• I will finish the proposal by 6 p.m. today (it needs to be completed by that time). 
• I will be working until 6 p.m. today (continuous activity during that timeframe).

By vs. Beside: Here, ‘beside’ means next to something, whereas ‘by’ means next to something but also indicates an agent, means, or deadline. If there is a need for precision in meaning, then “beside” may sometimes be preferred to “by”. 

For example:

She sat by the window. (next to the window)

She sat beside the window. (Directly next to the window)

The choice between each word depends on the exact relation that we denote by the respective word: deadline vs. duration, contact vs. general area, or strictly adjacency vs. a broader sense of nearness. 

How to Tell Which Part of Speech ‘By’ Is in a Sentence

In case of uncertainty, use this brief checklist: 

Analyze what comes after the word ‘by’. In case there’s a noun or pronoun following it, which connects the word to the rest of the sentence, then ‘by’ is a preposition.

Analyze whether it can stand alone. If there’s no other word coming after ‘by’ and the word modifies the action expressed by the verb, then it is an adverb. 

Analyze whether the word functions as a noun. If the word ‘by’ serves as the subject of the sentence and it talks about some planned pause or automatic advancement, then ‘by’ is a noun. 

Watch out for common phrases. Here the word is used in some fixed expressions such as by heart or by the way; treat it as one element. 

A bit of practice will help you get into the routine and understand how to interpret the word in any context. 

Frequently Asked Questions

1. What part of speech is ‘by’?

‘By’ is an adaptive word that works mostly as a preposition or an adverb and can sometimes be a noun, typically the noun form of the term bye week in the field of sport scheduling. 

2. What are examples of ‘by’ as a preposition? 

When used as a preposition. ‘By’ can demonstrate the person or thing that did an action, as in the window was opened by the intruder, or proximity to something, as in the chair is by the desk. 

3. What are some examples of ‘by’ as an adverb?

As an adverb, ‘by’ can indicate a location that is close to the speaker or passing by something, as in ‘she stopped by the store’ or ‘the car sped by.’ 

4. Can ‘by’ be used as a noun?

Yes, though not very often. In the context of a noun, ‘by’ (spelled as ‘bye’) means a matter that is of minor significance or one that is neglected, specifically in terms of a week without any game schedule in sports. 

5. How can you tell which part of speech ‘by’ is in a sentence?

You have to analyze its relationship with the other parts of the sentence. If ‘by’ connects a noun or pronoun to the rest of the sentence, it is a preposition. If ‘by’ stands on its own but modifies a verb, then it is an adverb.