I'm also using it to check my Welsh. I'm not using it to translate English to Welsh. I'm writing the script in Welsh but after putting the text through the grammar checker, I'm also putting it into Google translate to see if it says what I meant to say. It also saves me typing out the English version which I will need in due course for the subtitles.
And mostly Google translate is pretty good... except when it isn't!
It's completely confused about the Ceubren yr Ellyll (Haunted Hollow Tree) which was featured in my last video. Suggested translations have been:
The guillemot
The dwarf cubicle