look for the meaning.
Ken traveled, visited, ate and learned......... he visited site, ate foods and learner cultures when he was traveling around the world...

sunilrawat wrote:Ken traveled around the world, visited historic sites, ate native foods, and learned about new cultures. INCORRECT

Ken traveled around the world, visiting historic sites, eating native foods, and learning about new cultures. CORRECT

How do we differentiate main clause from verb phrases?
Is there a rule?

yes ing form i.e over herevisiting modifies the verb of the previous clause i.e over here traveled

first sentence is a fragmented sentence as it's not necessary that events visited,ate and learned happened at the same time when Ken travelled around the world

If the 2nd verbs are DESCRIBING the 1st verb, then use -ing as here.

"visiting", "eating" and "learning" are all things he did when we "traveled."

The first choice makes is seems like these were 4 separate actions, but the last 3 were a PART of the first 1.

Can someone help me with this?

The OG says,

.. based on cultivation of crops like corn and beans, the harvesting of fish and shellfish, and exploting other wild..

is NOT parallel

and

.. based on the cultivation of crops like corn and beans, the harvesting of fish and seafood, and the exploitation of wild..

IS parallel.

Howcome? The first one has all three gerunds and the second doesn't. Are they basing it on the fact that 'the' comes before each of the words?

Please help!

.. based on cultivation[NOUN] of crops like corn and beans, the harvesting[Noun] of fish and shellfish, and exploting[verb] other wild..

is NOT parallel

and

.. based on the cultivation of crops like corn and beans, the harvesting of fish and seafood, and the exploitation of wild.. In this option all are nouns

As a rule you cant compare noun and verb.

Gunjan has the main idea behind it, although sometimes we will see nouns in gerund form. Parallelism ideally has the same form (so having "the" in front can be nice!) but more importantly uses the SAME parts of speech.

So we have two choices:

cultivation, the harvesting, and exploiting (three different forms)

VS.

the cultivation, the harvesting, and the exploitation (all in the same form)

See how the second one is super-pretty and in the exact SAME form. Parallelism!

"Exact same form"...I was wondering if this is a correct usage as per GMAT. Shouldn't it be exactly same form or Exact, same form ?

VivianKerr wrote:Gunjan has the main idea behind it, although sometimes we will see nouns in gerund form. Parallelism ideally has the same form (so having "the" in front can be nice!) but more importantly uses the SAME parts of speech.

So we have two choices:

cultivation, the harvesting, and exploiting (three different forms)

VS.

the cultivation, the harvesting, and the exploitation (all in the same form)

See how the second one is super-pretty and in the exact SAME form. Parallelism!