Hi all
I am curious to know if the applicant of a Partner Visa is given the choice to have their interview in English or their first language? And does anyone have any opinion on the English level question in the applicant's application? What do you consider is 'functional and better than functional?'

For interviews it'll depend on the applicants english ability and/or ability of the CO/interviewer in the applicants language, som interviews being held in countries outside of the applicants country.

The question on the application form is more for data records/analysis and functional english would be that considered as basic enough comprehension to get by in an english speaking country with vry little help, even if comprehension is not speedy and communication is haltingly.
Many non english speakers go through a phase of listening to english words, converting the meaning of them into their own language to do the reasoning for a response and then convert that nack into english - still functional you could say and I think if you have a look at GSM english requirements you might find that functional for a secondary applicant is an IELTS score of 4.5.

Better than functional is going to better than 4.5 and someone who can converse meaningfully and readily would be considered to have better than functional.