Below is an exercise from this website. I'd like to ask if the sentence is correctly punctuated. Should not there be a comma between whale and looking?
My dad spotted the whale looking through his binoculars.
The phrase is nonrestrictive (nonessential) since the subject dad can be identified with or without using the phrase.
It's a case of failing to identify the correct antecedent...
We know the whale is rather unlikely to be in possession of binoculars, but it kind of sounds like it might be.
Dropping a comma in there would remove all doubt.
My dad spotted the whale, looking through his binoculars.
Because it's so obvious in this case, you could make an equal claim for either being valid, but there are constructions where clarity might be required.
My dad shook hands with his friend the horse standing beside him.
You might just want a comma in there ;)
One morning I shot an elephant in my pajamas. How he got into my pajamas I'll never know.
That's a joke. It relies on an ambiguity in English grammar. On the one hand, the phrase "in my pajamas" is in a good place to modify the verb "shot". On the other, it's in a good place to modify the noun "elephant". Grammar alone can't tell us which word this phrase modifies.
My dad spotted the whale looking through his binoculars.
This sentence has the same structure and the same ambiguity as the first sentence of the joke. The phrase "looking through his binoculars" is in the right position to modify either the verb "spotted" or the noun "whale".
It is not in the right position to modify "dad" as either a restrictive or nonrestrictive phrase.
The model sentence is correctly punctuated.
My dad, looking through his binoculars, spotted a whale.
When the participial phrase does modify "my dad" directly, then we can use parenthetical commas to mark that it is nonrestrictive.
