How to use "prior to"

What Does "prior to" Mean?

• Grammatical function: It expresses a temporal relationship, specifically indicating that one event or state occurred before another. It acts as a preposition followed by a noun phrase or gerund.
• Typical sentence position: It can appear in the initial, medial, or final position of a sentence, depending on the desired emphasis.
• Register: Formal

How to Use It

• Syntactic patterns: "Prior to" is typically followed by a noun phrase, gerund (verb ending in -ing acting as a noun), or a date/time reference. It is often preceded by a main clause describing the later event or state.
• Punctuation rules: When "prior to" introduces a phrase at the beginning of a sentence, a comma usually follows it. When it appears mid-sentence, commas are generally not needed unless the phrase it introduces is non-restrictive (provides extra, non-essential information).
• Grammatical flexibility: It can start a sentence. It can be moved around, though sentence-initial placement is common for emphasis. It is not typically negated directly; instead, the sentence would be rephrased to express the opposite meaning.
• What sounds unnatural or incorrect: Using "prior to" in very informal contexts might sound overly formal. Also, using "prior than" is grammatically incorrect.

Real-World Examples

These examples are sourced from prior to on Ludwig.guru.

"prior to the burial." — The New York Times

"Prior to 1990, no one came here." — The New York Times

"Prior to this, anatomy was." — Forbes

"Prior to that it was published quarterly." — BBC

"Cells were counted prior to plating." — Plosone

Examples sourced from https://ludwig.guru/s/prior+to

Similar Phrases and Alternatives

Phrase	Context
before	Most common and versatile alternative; suitable for formal and informal contexts.
earlier than	Emphasizes the time difference more directly.
ahead of	Suggests being in front of something in time or progress.
previous to	A near synonym, though "prior to" is more common.
in advance of	Highlights preparation or anticipation.
preceding	More formal, often used in academic or technical writing.
up until	Indicates a duration leading to a specific point in time.

Common Mistakes

• Learners often incorrectly use "prior than" instead of "prior to", confusing it with comparative structures.
• Sometimes, "prior to" is used in overly informal situations where "before" would be more appropriate.
• Omitting the comma after "prior to" when it begins a sentence, though not always strictly required, can affect readability.

Quick-Reference Summary

Expression	Function	Register	Typical Position
prior to	Indicates an event or state occurring before another	Formal	Initial, medial, final

FAQs

Where can "prior to" be placed in a sentence?

"Prior to" is quite flexible and can appear at the beginning, middle, or end of a sentence. Sentence-initial placement (e.g., "Prior to the meeting,...") often emphasizes the temporal relationship, while medial or final placement (e.g., "... prior to the meeting.") provides the information as an aside or detail.

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What's the difference between "prior to" and "before"?

While both "prior to" and "before" indicate that something happened earlier, "prior to" is generally considered more formal. "Before" is a more versatile and commonly used term that fits well in both formal and informal contexts, while "prior to" is preferred in formal writing or when a more sophisticated tone is desired.

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Is it correct to say "prior than"?

No, it is incorrect to say "prior than." The correct expression is "prior to". This is a common mistake made by English learners who are likely confusing it with the comparative structure using "than" (e.g., "earlier than"). Remember that "prior" always takes the preposition "to" when indicating a temporal relationship.