You really should stay in UK for this . Britain has a great tradition of amateur choirs for all genres, . Had you posted earlier we would have directed you towards the rehearsals of the choirs local to where you were staying but especially those of CUMS ( Cambridge University Music Society ) Choir.Edited: 05 October 2018, 20:57
Let's start with this is the food and travel forum and the enquiry has absolutely nothing to do with any of that!
Next, the OP asked about choirs and choral communities in Prague, Venice and unspecified locations in Belgium. While none of those countries are English speaking, there will be English speakers to be found there. Granted destinations in the UK will, by default, offer English speaking rehearsals, if the trips does not include the UK, offering advice for either Chester or Cambridge is not likely to be relevant.
For workshops, in any language, you are likely to need to contact a music school of some kind. However, many churches, chapels and cathedrals may well have choir practices and rehearsals ahead of major events in the religious calendar to which the public could be invited or at least be allowed to be present, if not causing a disturbance.
I have walked into churches in Venice during both choir and organ practice. I have done the same in Prague many a time, although these events are so commercial there, that some rehearsals require a fee to attend, bizarrely. On none of these occasions, did I need to speak a word of the local language, being able to only understand English should not be a barrier to attending. As to Belgium, I cannot comment - my only quasi religious experiences was time with monks which was more about the beer than the music!
You need to post on the destination forum for the places you will find to get relevant info. You need to provide your dates when you will be in each destination and explain why you need English commentary.
I noticed that you inadvertently posted your question in the Food and Travel Forum, so I have moved the topic on your behalf to the Belgium Forum.
TripAdvisor Community Moderator
I suggest the OP google "english-speaking choir" plus the name of any Belgian CITY being visited. Only expat (e.g. British/ International School) choirs are likely to be working in English - and I am not sure that they would welcome tourists - or any outsiders not actually moving to the city concerned - at rehearsals. For Brussels, I imagine the best bet for attending a performance/ rehearsal in English would be the Brussels Choral Society, formerly the "Society for Suppressed Songsters" (https:/…).
As for workshops, google singing workshop and the name of the city - but in Belgium these are likely to be held only during school holidays, and again, if it has to be in English, at foreign, English-speaking institutions like the British or American schools (reverse whatever you would do if looking for a FRENCH choir in Australia....). You could also google expat forum + name of city, and ask there about choirs set up by English-speaking foreigners in the city concerned.