Fluent interactive conversation usually owes more to rapid short phrases than to long complex sentences. If you can have a few dozen of these phrases firmly in your head, ready for use, you should find the wheels turning more easily when you engage in dialogue with others.
Note that dell, which is frequent in conversational phrases, may be 'reduced' to dr' before a vowel in forms of bos; and otherwise to der or dre; and it can be written that way too.
[A] wosta
You know (filler)
An very poynt y honen
That’s just the point
Anhegol dell
It’s incredible that
Anodho ny’m deur
That doesn’t concern me
Assentys
I agree
Bëdh sur
Rest assured
Bohes lycklod
Not likely
Bÿth na lavar a’n dra
Don’t mention it
Cales yw assentya
It’s hard to agree with that
Càm na worama
I haven’t the faintest idea
How should I know?
Côwsel dhe blebmyk
Frankly
To be honest
Cudyn vëth
No problem
Dell dal consydra
It’s worth bearing in mind
Dell dheseva’
I assume
Dell dyba’ / dybam
I think
I suppose
Dell esoma vy ow qweles an dra
As I see it (playing for time)
Dell eus govenek dhèm
I hope so
Dell gresa' / gresam
I believe
Dell hevel
Apparently
Dell hevel dhèm
I think
I believe
Dell leverys
As I said
Dell soposys
As I thought
Dell vadna’ brusy
If you ask me
Dell welama vy
As I see it
Dell wodhyr
Of course
Dell wrugam tyby
As I thought
Dell yw apert
Evidently
Obviously
Dell yw dhe wetyas
I expect
Dell yw gàs plesour
As you like
Dell yw ôpynwelys
As anyone can see
[Dell yw] res alowa
I must admit
You must admit
Dhe dhyspûtya martesen
Well I don’t know about that
Dhe’m breus vy
In my opinion
Dhe’m tybyans vy
To my way of thinking
Dhe’m desef
I assume
Dhe’m golok
As I see it
Dhe’m govenek
I hope
Dhe wovenek gwir
Let’s hope so
Dowt vëth
No doubt
Don’t worry (expressing certainty)
Eâ
Yes
Er y wu
Unfortunately
Worse luck
Flows
Nonsense
Flows ha whedhlow
Rubbish
Furneth yw hedna
That’s a good point
Gas ny dhe weles
Let’s see
We’ll have to see
Ges a wrêta
You’re joking
Ges vëth
Seriously
No kidding
Goda-chauns re’th fo
Good luck with that
Govyn y hyller dâ
One might well ask
Gwir glân
That’s right
Gwir oll
That’s right
Gwir poran
That’s quite right
Gwir yn tien
That’s quite right
Gwra pêsya
Go on
Gwydn ow bÿs
I’m delighted
Ha ny ow côwsel
By the way
Ha ny ow côwsel a'n dra
And while we’re on that
Heb bos gwir oll
Not exactly
Heb bos res porres
Not necessarily
Heb mar
Of course
Certainly
Hèn yw dhe leverel
I mean
Hèn yw lowr
Enough of that
Hèn yw onen dâ
You must be joking
In neb maner leverel
In a manner of speaking
I’n gwelha prës
Fortunately
I’n gwetha prës
Unfortunately
Lawl dell wrug kyns
As I’ve said before
Lawl dell wrug namnygen
As I’ve just said
Lower lycklod
Probably
Quite likely
Ma ken breus dhèm
I disagree
I see it differently
Martesen
Perhaps
Maybe
I suppose so (when implicitly disagreeing)
Meur dhe dhowtya
I doubt it
Nâ
No
Na fors
Never mind
Naneyl obma nag ena
That’s not the point
Neb gradh
Up to a point
Neb styr
In a sense
Ny’m deur
I don’t care
Ny woram convedhes
I don’t understand (why something is the case)
Ny wora’ màn
I’ve no idea
Nynj esom ow cachya dha styr
I don’t quite get your point
Nynj om’ assentys
I disagree
Nynj oma sur
I’m not sure
Nynj yw badna perthynek
That’s got nothing to do with it
Nynj yw marth
No wonder
Ny rov oy a hedna
I’m not bothered about that
Ny vern
It doesn’t matter
Ogh, tybys ken oma
Oh, I wouldn't say that (mildly protesting disagreement)
Osta sad?
Are you serious? (as exclamation)
Ot an dra
The question is
Ow styr yw hebma
What I mean is
Pëth a vynta leverel?
What do you mean?
Pùb lycklod
I dare say
Qwestyon dâ
Good question
I wonder
Re’m fay
Wow
Re’n ow thas
Gosh
Good grief
Scant y fia marth
I shouldn’t be surprised
Scant yw marth
It’s hardly surprising
Soweth
Unfortunately
More’s the pity
Sur
Of course
Th’esom’ in nevow
I couldn’t be happier
Tra sur
Sure thing
Tra vëth ny vern
It really doesn’t matter
Tybyans dâ
Good idea
Good thinking
Ùnpossybyl
Impossible, out of the question
Unver oll
I totally agree with you
Unweyth arta, mar pleg
Could you repeat that please?
Wàr an tu aral
On the other hand
Wàr dha gàm
Steady on
Not so fast
Wèl mara’th teur
Well if you’re interested
Wèl otta sy
Well there you are
Yn tefry
Indeed
Yn tien
Absolutely