First, while sending invitations set the language as Czech. 
 

And enter the following code in Look and feel menu
Selecting the "Advanced" tab
Click on the green “Add Custom CSS" button
Paste the following in to the box that appears:

.LanguageSelectorContainer{
display: none;
}

Hi,

Set your base language to Czech (you don’t have to rewrite from scratch to change the base language) and then hide your English version from the respondents in the translation tab :

Hi,

Set your base language to Czech (you don’t have to rewrite from scratch to change the base language) and then hide your English version from the respondents in the translation tab :

 

Thank you, ​@vgayraud. My issue with this option is that, when I select Czech as my base language, I lose my Czech translation, and then I don’t seem to be able to simply upload the Czech translation anymore as the base language. Since it is a long survey with custom code, it will take some time to manually copy and paste the entire Czech version under the base language. I have tried downloading the Czech translation and then uploading it, but it doesn’t recognize this as a translation. Do you know if there is an automatic way of uploading a translation file to become the base language? If it were possible to do this in a straightforward way, then this option would work well indeed. If not, I could do it manually, but it would be better if I could automatize it. 

Thanks again!!

Thank you! ​@jbk I tried this, but unfortunately it doesn’t seem to work for me. I don’t have the “Advanced” tab in the look and feel menu, so I included it under Look and feel/Style/“Custom CSS”. But when I test it using the survey link or preview, I still see the language selector with both languages.

​@manumrm,

Use this for Simple layout:

#language-selector-container { display:none; }

#language-selector-container { display:none; }

This works great, thank you! 

Hi,

Set your base language to Czech (you don’t have to rewrite from scratch to change the base language) and then hide your English version from the respondents in the translation tab :

 

Thank you, ​@vgayraud. My issue with this option is that, when I select Czech as my base language, I lose my Czech translation, and then I don’t seem to be able to simply upload the Czech translation anymore as the base language. Since it is a long survey with custom code, it will take some time to manually copy and paste the entire Czech version under the base language. I have tried downloading the Czech translation and then uploading it, but it doesn’t recognize this as a translation. Do you know if there is an automatic way of uploading a translation file to become the base language? If it were possible to do this in a straightforward way, then this option would work well indeed. If not, I could do it manually, but it would be better if I could automatize it. 

Thanks again!!

Yes, this is very frustrating that you lose the translation when changing the base language…

I saw that on the Ideas platform here on Community, there is an idea open for fixing that behavior, it is EV-2432. I just gave it an extra vote.