‘At first sight’ vs. ‘at the first sight’ in English

by Jakub Marian

Tip: See my list of the Most Common Mistakes in English. It will teach you how to avoid mis­takes with com­mas, pre­pos­i­tions, ir­reg­u­lar verbs, and much more.

When used with a noun, the adjective “first” is almost always preceded by “the” or a possessive determiner, such as “my”, “your”, “his”, etc.:

I didn’t take the first bus.
This is my first wife.
Neil Armstrong was the first person on the Moon.

When used in its literal sense of “the first time of seeing something”, “at the first sight” is not an exception. You can say, for example:

He fainted at the first sight of blood.

However, “at first sight” is much more commonly used in the idiom “love at first sight”, which means “an instantaneous/immediate attraction”. It is used without an article in this case:

correct It was love at first sight.
unnatural It was love at the first sight.

“Love at first sight” is the most common way to employ this phrase, but “at first sight” can also be used in the sense of “based on the first impression”:

correct The topic looked complicated at first sight.
unnatural The topic looked complicated at the first sight.

Again, there is no article when the phrase is used in this sense. Another variant of this idiom is “at first glance”, which follows the same rule.

By the way, if you haven’t read my guide on how to avoid the most common mistakes in English, make sure to check it out; it deals with similar topics.