Learn Swedish: Bordsgrannen skrattade sig hes vid ostbrickan. - The table neighbor laughed himself hoarse at the cheese board.

This is a resultative reflexive construction, which is the main focus of this lesson. The verb skratta (to laugh) isn't normally a reflexive verb. However, by pairing a reflexive pronoun like sig with an adjective like hes, you describe the physical result of the action. It shows that the neighbor laughed until they became hoarse.

Does the adjective hes need to agree with the subject in this type of construction?

Yes, it acts as a predicative adjective and must agree with the subject in gender and number. Because bordsgrannen is a singular en-word, we use the base form hes. If the subject were plural, such as bordsgrannarna, the adjective would take the plural form hesa (de skrattade sig hesa).

Why use the preposition vid for 'at the cheese board'?

vid indicates being situated next to, by, or gathered around something. This is the natural preposition for sitting around food or a table. If you used på, it would sound like the neighbor was physically sitting on top of the cheese board!

Is bordsgranne a standard word in Swedish?

Yes, it is a very common and culturally useful compound word. A bordsgranne is the person sitting next to you, or sometimes directly across from you, at a dinner party, wedding, or any social gathering around a table.