
According to https://www.oxfordlearnersdictionaries.com one meaning for the adjective free is – costing nothing
Sentences with free can look like this:
Something is free…
My coffee was free.
Or we can do something for free…
I can watch for free online.
Maybe you can guess the grammar already.
A noun is free
These baseball tickets were free!
We verb for free
We can watch the game for free.
*If we get something (a noun) we can say for free because get is a verb.
I got these shoes for free!
Alex works at the theater so he gets tickets for free.

*NOTE*
I received a comment from Warsaw Will that pointed out that…
…after a verb, the adverb “free” is just fine without “for.”
You can eat free in my restaurant whenever you like.
This is a natural example of a verb (eat) followed by the adverb free without the preposition for.
I wanted to make a simple example that ESL students could understand but I shouldn’t have said that…
…we need to say for free because get is a verb.
This is not true. For me personally using FOR FREE with a verb is natural, but we don’t have to. The example below is also perfectly acceptable.
I got these shoes free!
Thanks again to Warsaw Will for the constructive feedback on my post. You can see his English blog @ http://random-idea-english.blogspot.com/
Free @ oxfordlearnersdictionaries.com
https://www.oxfordlearnersdictionaries.com/definition/english/free_1?q=free
Check out these other great posts!
Thank you Teacher
You’re welcome! Thanks for leaving a comment 👍
I’m afraid I don’t quite agree. Yes, after a noun we use the adjective “free”. But after a verb, the adverb “free” is just fine without “for”. In fact the use of “for” is relatively recent, and when I was young was often considered “wrong”.But I don’t think the fact that this idiomatic use is now unobjectionable makes it a rule.
From Michael Swan’s Practical English Usage:
“The adverb “free” (used after a verb) means “without payment” :
‘You can eat free in my restaurant whenever you like”
In Google, numbers are pretty even, with or without “for”, the latter including American instances.
Thanks for the comment! I have updated my post as per your feedback 🙂