Breakdown of Lägg grejen på bordet.
bordet
the table
på
on / at / for (wait for) / in (believe in)
lägga
to lay, to put down
grejen
the thing (informal)
Questions & Answers about Lägg grejen på bordet.
Why does this sentence use lägg for "put" instead of ställ or sätt?
In English, you can "put" almost anything anywhere, but Swedish requires you to be specific about the object's physical position. You use lägga (command form: lägg) when you put something down so it rests flat or horizontally, like a book or a pair of keys. If the object were meant to stand upright, like a vase or a glass, you would use ställa.
I usually use "sak" for "thing". What is the difference between grejen and saken?
Both mean "the thing", but they have a difference in tone. En sak is the standard, neutral word for a thing or an object. En grej means exactly the same but is much more informal and colloquial. You will hear grej and grejen constantly in everyday spoken Swedish!
Since lägg is the command form, what does the rest of this verb's conjugation look like?
The infinitive is lägga. It is a very common verb but slightly irregular, so it is a good one to memorize. The present tense is lägger, the past tense is usually spoken and written as la (though you will see lade in formal writing), and the supine form (used with "have") is lagt.