What aredo you doing if you have to use your talspeaking skills in a foreign language but it's at a challenging level for you?

Or you have to go to some local office and talk to a tired and unimpolite person to solve a personal issue.

What technicques do you use?

How you cancan you use this very short time in an effective way?

And how do you not forget all those words when you start talking?

And when you hear a clear but such an unpleasant "Hah?!

Or even - "It's all Greek to me.

I just don't understand ."

MAy aybe you have a secret word?

May be a gesture?

May be a spell?

And you will help all of us to talk to a Ggovernment office clerks with their "robotic" answers or bus drivers, who closinge doors right as you arrive.

"a" is used for singular things but you said "clerks" which is plural so doesn't use a "a"

Or be prepared to shine when you have to give unexpectedly give an interview in Spanish to the BBC or National Geographic.

What aredo you doing if you have to use your talking skills in a foreign language, but it's a challenging level for you?

"What are you doing?" asks what the person is doing at the moment.

Or you have to go to some local office and talk to a tired and unimpolite person to solve a personal issue.

What technicques do you use?

Good. In this sentence you need no correction for the verb.
(You didn't write "are you using?"

And how do you not forget all those words when you start talking?¶

Also good: And how do you remember all those words when you start talking?

And when you hear a clear but such an unpleasant "Hah?!

I don't think "but" works here because there isn't a contrast between "clear" and "unpleasant."

MAy aybe you have a secret word?

"Maybe" is one word.
But you could say "It may be that you have a secret word," as a statement.

May be a gesture?

May be a spell?

And you will help all of us to talk to a Government office clerks with their "robotic" answers or bus drivers, who closinge doors righjust as you arrive.

Or be prepared to shine when you have to give unexpectedly have to give an interview in Spanish to the BBC or National Geographic.