Formal and informal language.

[TheNewOne]

How coarse or inappropriate to use these words “wanna, gonna, gotta, etc” in formal language? Should I avoid them in my formal and informal language? I read in a book written by a Russian-American woman that it was not good to use them even in informal language. Is it true? I like to use these words instead of normal “want to”, "going to", but I never paid attention to the fact that I might sound grossly. Also I like to insert different expressions in my speech, but I don't know how appropriate to use them in a talk with a person (native speaker) who I don't know very well or meet for the first time. Of course they understand that English is a foreign language for me (but there were some native speakers who laughed at my wrong expressions and I was just like this smiley ), so I don't want to feel shame again because of incorrect use of some word and expressions. Can you advise me how to improve this side of my English?
TIA

[5jj]

The pronunciations represented by the spellings wanna, gonna, etc are actually quite common in the informal conversation of even reasonably well-educated people, though many of them would deny it.

The problem is, that for many native speakers, this just happens, without thinking. If you ask them, some will claim that they said want to, going to, etc', though they may admit that they said it quite quickly, with the result that it 'sounded like' wanna or gonna.

When non-native speakers use these pronunciations, they often make a deliberate attempt to use them, and the result can sound a little unnatural. I would suggest that you say the 'correct' forms, but do not make any real effort to say them distinctly in informal conversation. As your fluency increases, you will almost certainly sound more natural.

[TheNewOne]

fivejedjon
Thank you very much!
What can you say about the word "kinda"? Is it a filler word?

I guess my message is unclear to the forum users

[5jj]

What can you say about the word "kinda"? Is it a filler word?

It can be the conversational pronunciation of 'kind of' when 'kind' means 'type'; it sometimes appears to be a filler, though it seems to retain some suggestion of 'in this kind of way'

The glow worm is a actually a kind of (kinda) beetle.
So then he like smiled at me kinda friendly.- Informal.

I guess my message is unclear to the forum users

I don't find it so.

[Raymott]

How coarse or inappropriate to use these words “wanna, gonna, gotta, etc” in formal language? Should I avoid them in my formal and informal language? I read in a book written by a Russian-American woman that it was not good to use them even in informal language. Is it true? I like to use these words instead of normal “want to”, "going to", but I never paid attention to the fact that I might sound grossly. Also I like to insert different expressions in my speech, but I don't know how appropriate to use them in a talk with a person (native speaker) who I don't know very well or meet for the first time. Of course they understand that English is a foreign language for me (but there were some native speakers who laughed at my wrong expressions and I was just like this smiley ), so I don't want to feel shame again because of incorrect use of some word and expressions. Can you advise me how to improve this side of my English?
TIA

It's certainly inappropriate to use these terms in formal written English. Some of us would object to it in semi-formal English as well, such as on this site. The correct time to use these expressions in informal speech is when your fluency allows them to occur naturally.
As far as conversations with strangers go, you open your mouth and you take a chance; that happens even with people who speak the same language. At least you have an excuse for saying embarassing things!

[TheNewOne]

fivejedjon

So then he like smiled at me kinda friendly.- Informal.

Sometimes I talk like this. I don't know why I put in so many "kinda", that's why I started thinking that "kinda" was a filler.
Raymott

At least you have an excuse for saying embarassing things!

Thank you! I feel better now