Anyone who visits this museum will undoubtedly laugh.

[sadra1400]

Why do we need a "who" in the below sentence?
Anyone who visits this museum will undoubtedly laugh.

 

[Barque]

I'm not really sure how to explain that from a grammatical point of view, so let me try a different method.

This is one of your sentences:

When I go back home, I am too exhausted to do anything, never mind do the dishes.

Why did you use "When"? It's much the same principle.

 

[sadra1400]

I'm not really sure how to explain that from a grammatical point of view, so let me try a different method.

This is one of your sentences:

Why did you use "When"? It's much the same principle.

When I translate the above sentence into Farsi without "who," it is completely correct, but the example you gave is completely wrong in Farsi without "when."

 

[Barque]

I assume that was a joke!

But in case it wasn't, there's no point going by how it sounds when you translate it into Farsi. English and Farsi are different languages with different grammatical rules.

Anyone who visits this museum will undoubtedly laugh.

Anyone visits this museum will undoubtedly laugh. This is wrong. To make it correct, you need the pronoun "who" at the beginning of the relative clause. Otherwise it sounds as if the relative clause is connected directly to "Anyone".

 

[Rover_KE]

You could omit 'who', sadra, if you change 'visits' to 'visiting'.