
...and if I can figure out a way to do so
and sound SINCERE, I will.
The Big Bang Theory Season 4, Episode 9

I sense that's not SINCERE,
although I have no idea why.
The Big Bang Theory Season 3, Episode 11

Not to "Sin City" but to "SINCERE city."
The Big Bang Theory Season 9, Episode 13

If you're interested in making
a SINCERE effort to be a good teacher...
The Big Bang Theory Season 8, Episode 2

Did you make the apology
as SINCERE as I would have?
The Big Bang Theory Season 9, Episode 23