The phrase "forget for a second" is correct and can be used in written English.
It is commonly used to indicate a temporary pause or break from thinking about something. Example: "I know you're stressed about the presentation, but forget for a second and let's enjoy this beautiful sunset."
Forget for a second that a week ago, he and his mighty Patriots were being crushed by the Browns and instead be mesmerized by the game-turning tantrum Brady unfurled on his own team in Sunday's victory over Pittsburgh.
Let's forget for a second the Jets' byzantine route to the playoffs.
Egg mould, £5, from justmustard.com Lest you be allowed to forget for a second, Valentine's Day is approaching.
Even from a distance, it was easy to distinguish between them — and forget, for a second, that Tebow and Sanchez pass with different hands.
Let us forget, for a second, that this is a man who's only going to be in office for nine months of the 17 years in question.
(O.K., forget for a second that the Giants are led by the two-time Cy Young Award winner Tim Lincecum and the Colts are quarterbacked by the legendary Peyton Manning. It makes the story less charming, so work with us here).
When the stage was reduced to silence at the point of a wizard's wand, I forgot for a second that there was nothing spooky in the silence, that this was simply actors not speaking.
Forgetting for a second that you put "hate it" and our client's product in the same ad, let's talk about the legal implications.
Forgetting for a second that consumers of conservative media, like the Daily Caller, tend to be some of the least informed and least interested in exploring alternative viewpoints, Greer seems to have very little understanding of what these students are doing.
