Is there a single word for "very likely"?

Question

I want to say:

They are very likely to be different.

But I find it a bit wordy, so I was wondering is there a single word that can be used like:

They are _______ different.

I know maybe I can use basically here, but that seems to change the original meaning a bit to me, is that right?

Edit:
Is there a word that is stronger than "probably" in terms of probability?

Edit:
The context could be imagined as, I have asked some people from the streets to fill a questionnaire, but I can't be 100% sure if I have asked the same person twice, though it is very unlikely to happen.
So I want to say something like "These people are very likely to be different from each other."
Sorry for the terrible explanation.

Answer 1

Your question seems to revolve around the probability that two things are different, not the degree to which they are different. Using basically refers to the degree they are different.

A quick look at dictionary definitions shows that probably is synonymous with most likely, however from usage, why would the phrase most probably then exist?

likely to be different

means a greater than a 50% chance

most likely to be different

means something much greater than 50%, for example 90%

are different
definitely different
inherently different
completely different
totally different

implies they are different with certainty (probability of 1.0)

To me, most likely has a greater chance of being different than just probably, whereas likely and probably are equivalent. However, in your example, most likely still leaves the door open that they may be different, which makes phrasing difficult since the degree can always be modified by more or very which would make it two words, not one word.

Answer 2

For your edited-in example, "I can't be 100% sure if I have asked the same person twice, though it is very unlikely to happen" says it more clearly than the "They are ____ different" form would, but if determined you could consider using "presumed", "presumably", "assumed", "typically", or "assumably" (an ugly word IMHO).

If you want a separate statement, perhaps "It is unlikely that many people will be surveyed multiple times." or - stronger - "There's only a remote possibility of the same person being accidentally surveyed multiple times."

Answer 3

You can say

They are apt to be different.