Phrasal Verbs what are they? Why do native speakers use them so much? Why are they so confusing?

Native English speakers are constantly using phrasal verbs and they use them with such ease but for someone learning English they can be very confusing and very annoying.
They are very common in English as they allow the conversation to be informal or casual. They are not recommended in formal writing.
They can also be very confusing for learners because they often have many meanings. UGH!
What is a phrasal verb?
It’s a verb plus a particle – either a preposition or adverb that changes the meaning of the verb.
Hang Out– Spend time with people
I love to hang out with friends on the weekend.
Take off – To remove
Please take off your coat
Take off– To leave
The plane took off
I have to take off at 3.30pm
Run Into – To meet by accident, not arranged , unexpected.
I ran into Bob at the cafe.
Separable or inseparable?
Sometimes the preposition/adverb is placed either after the verb or after the object 
Pickup– To collect
I will pick up John from school.
I will pick John up from school.
However if the object is a pronoun it must be placed after the verb
I will pick him up from school.
Some phrasal verbs can’t be separated
Come across– find by accident
I came across some old photos while cleaning the house.
Get rid of– To throw out or remove
Get rid of those old clothes.
Why don’t you try out phrasal verbs and start using them in everyday conversation.