The fun way to do this, as well as the obvious interpretation of the rules, would be to have them imitate phrases perfectly, sounding like the original speaker, but using them in approximately the sense they originally heard them. So their voices can change completely from sentence to sentence - one being a dwarf they heard speaking yesterday, the next sentence being a small elf child they heard ten years ago, and the third being something you said to them three months ago.

They understand what phrases and sentences mean, but if they can't break down phrases into words and use the words individually, they're still fairly limited by their curse. They would sound a bit like Dilbert's pointy-haired boss, who tends to come out with phrases and clichés that belong in a subtly different conversation.

This would be an interesting challenge for a player who was usually verbally adroit. Precedents for even more extreme versions exist in the Librarian from Terry Pratchett's Discworld series who manages to get by with just one word, "Oook", and Mr Punch in the classic Punch & Judy show, most of whose lines are "That's the way to do it!"

The main problem with playing a Kenku this way would be avoiding humour in serious moments of the game.

Having played with Kenku and seen others play with Kenku Characters, here is what I've learned.

Kenku mimicry should be inconvenient right until it stops being fun

The limitation on Kenku speech is a fun quirk that makes for hilarious moments at the table. However, spending many minutes browsing sound clips or a phrase list options to say is going to reduce both your and your party member's fun.

Try your best to repeat phrases spoken recently around you, but don't feel the need to justify every single common word or phrase. Talk to your DM about his leeway on you improvising things but I imagine he's fine with you saying anything as long as it makes sense you would have heard someone at some point say it. I imagine you aren't playing an infant Kenku, you've probably picked up some language.

Soundboards

I think using a soundboard app or site as a way to communicate your kenku impersonating something other than speech is potentially worthwhile, but I would say likely only when you can queue it up quickly or know in advance what sound you want to do, so you don't interrupt a conversation flow to browse on your phone.

Notes

Things that would be important to make notes of (handwritten or otherwise) would be:

• Names (You cant say someone's unique name if you haven't heard it)
• Anyone saying something incriminating/secret (Valuable to be able to repeat this to others)
• The sounds of various monsters you fight

So in conclusion: For speech, don't hamstring yourself too much with restrictions so that it stops being fun or you stop trying to talk at all. Soundboards are useful/fun in specific cases and notes are useful for recording very specific words and sounds which are unique.