Rules for Prepositions

1. Pair Them Properly

A preposition is a handy tool when you want to connect a verb to the rest of a sentence. However, you need to choose the correct preposition based on the verb that comes before it.

For example:

• George should listen to our advice.

• You’re capable of anything you set your mind to.

• Shelly’s been preoccupied with work lately.

• The teacher is concerned by Janette’s consistent tardiness.

• Employees are prohibited from smoking on company property.

Each of the prepositions in bold are the only acceptable prepositions to follow the underlined verbs that precede them. For example, it wouldn’t be grammatically correct to say "listen of" or "capable to."

2. Watch What Follows Them

A noun or pronoun (known as the object of the preposition) should always follow a preposition. A verb can't be the object of a preposition.

For example:

• Correct - The bone was for the dog. (The preposition for is followed by the noun the dog)

• Incorrect - The bone was for walked. (The preposition for is followed by the verb walked.)
  
  

• Correct - Place the spoon by the knife. (The preposition by is followed by the noun knife.)

• Incorrect - Place the spoon by the eating. (The preposition by should not be followed by the verb eating.)

You may have seen words that look like verbs following the word to, such as in “I like to ski” or “These boots are for skiing.” However, in these examples, ski and skiing are not acting as verbs — they’re part of phrases that are functioning as nouns. To ski is an infinitive, while skiing is a gerund that functions as a noun to follow the preposition for.

3. Avoid Using Prepositions at the End of Sentences

Because prepositions must be followed by a noun, they should rarely appear at the end of a sentence. For example, it’s generally not correct to say:

• The table is where I put my books on.

• Can I turn in my homework after?

• Who does the prize go to?

While ending a sentence with a preposition is generally acceptable in casual writing, it’s still frowned upon in formal writing. In most cases, you can easily rewrite the sentence to avoid ending with a preposition or add an object of the preposition to clarify meaning. For example:

• The table is where I put my books. (Removed on)

• Can I turn in my homework after school? (Added school as a preposition)

• Who won the prize? (Rewrote the sentence with the verb won)

4. Never Substitute ‘Have’ for ‘Of’

A common grammar mistake is to replace have with of in a sentence. For example:

• I should of come over.

• He could of helped if he wanted.

• We would of been late if we’d missed the train.

When using modal verbs such as should, could and would, you need to pair them with a helping verb (have), not a preposition, because you’re not linking two parts of a sentence together. That’s why these sentences should actually read:

• I should have come over.

• He could have helped if he wanted.

• We would have been late if we’d missed the train.

People say of instead of have in these situations because they’re thinking of the contractions for “would have” (would’ve) or “should have” (should’ve). When you say the contractions out loud, they do sound like of — but they’re not.

5. Don’t Confuse ‘In’ and ‘Into’

It’s also common to mix up the prepositions into and in. When you want to express motion toward something, use into. Reserve in for moments when you want to indicate a location. For example:

• I swam in the lake. (Indicating location)

• I walked into the pub. (Expressing motion)

• Look in the cupboard. (Indicating location)

• She drove into the city. (Expressing motion)

The same rule applies to out and out of. If you get confused about in and into, see if out would work, and if it does, use in. (If it doesn’t, use into).

6. Try Not to Mix Up ‘Than’ and ‘From’

It’s easy to confuse than and from, especially when pairing with the adjective different. They both sound correct, depending on how you’re used to saying it.

For example:

• You look different than your mother.

• You look different from your mother.
  
  

• This tastes different than your usual recipe.

• This tastes different from your usual recipe.

Both prepositions connect the adjective different to an object, which allows the sentence to compare the two nouns (subject and object). In formal writing, from is generally more accepted than than. The best options for these sentences would be:

• You look different from your mother.

• This tastes different from your usual recipe.

Peaceful Prepositions

Prepositions are the peacemakers of the English language. They join it all together with cohesion and clarity. For more on these peacemakers, check out:

• List of Common Prepositions and How to Use Them

• Of vs. For: Differences and Proper Grammar Use

• How to Use To vs. For Correctly