Prepositions are the "glue" of the English language, but they can be incredibly slippery. Since they often don’t follow strict logic—why do we get on a bus but in a car?—it’s easy to trip up.
Here is a breakdown of the most common preposition errors and how to fix them.
1. Common Word Pair Mix-ups
Certain verbs and adjectives are "married" to specific prepositions. Using the wrong one is a frequent mistake.

Incorrect	Correct	Note
Bored of	Bored with	Though "of" is becoming common in casual speech, "with" is the standard.
Married with	Married to	You are married to a person; you have kids with them.
Depends of	Depends on	This is a classic translation error from Romance languages.
Interested on	Interested in	You place your interest inside a subject.
Complied to	Complied with	You adhere to rules, but you comply with them.

2. Space and Time: In, On, At
These three cause the most headaches because they shift depending on the scale of time or location.
In: Used for enclosed spaces, cities, months, and years.
Error: "I'll see you on January." → Fix: "I'll see you in January."
On: Used for surfaces, days, and dates.
Error: "The meeting is at Monday." → Fix: "The meeting is on Monday."
At: Used for specific points and precise times.
Error: "I am in the entrance." → Fix: "I am at the entrance."
3. Redundant Prepositions
Sometimes we add prepositions where they simply aren't needed. This usually happens in casual speech.
Where are you at? * Fix: "Where are you?" (The "at" adds no extra meaning).
Discuss about the issue.
Fix: "Discuss the issue." (You talk about something, but you discuss something).
Return back.
Fix: "Return." (Returning implies going back; using both is repetitive).
4. The "Ending with a Preposition" Myth
You might have been told in school never to end a sentence with a preposition (e.g., "Who are you talking to?").
The Truth: In modern English, this is perfectly acceptable and often sounds more natural than the formal alternative ("To whom are you talking?"). Don't stress this one unless you are writing a very formal academic paper.
Pro-Tip: If you aren't sure which preposition to use, try looking up the verb in a learner's dictionary (like Oxford or Cambridge). They specifically list the "collocations"—the words that naturally hang out together.