The phrase "agree mostly" is correct and usable in written English.
It can be used when expressing a general consensus or partial agreement with a statement or opinion.
Example: "While I see your point, I must say I agree mostly with the alternative solution you proposed."
Alternatives: "largely agree" or "mostly in agreement".
I'm not sure what I spar about mostly with curlycurlew; I think we agree mostly.
The blame for this dismal state of affairs, Glasgow councillors now seem to agree, mostly lies with them.
Obtained MIPAS HCFC-22 time series below 10 km altitude are shown to agree mostly well to corresponding time series of near-surface abundances from NOAA/ESRL and AGAGE networks, although a more pronounced seasonal cycle is obvious in the satellite data, probably due to tropopause altitude fluctuations and subsidence of polar winter stratospheric air into the troposphere.
I agree mostly because in 15 years of hearing the tired mantra about an alien and encroaching Islam, the word "Muslim" has come to symbolise a thing beyond being Australian, a thing of chaotic violence and a carrier of a confronting and thick difference.
Pewforum.org 2010delivered a questionnaire to citizens in each state who were asked to respond, completely agree, mostly agree, mostly disagree, or completely disagree to the following statement: Evolution is the best explanation for the origins of human life on earth.
Participants were asked to mark their agreement with the items on a Likert-type scale with four possibilities (agree completely, agree mostly, disagree mostly, and disagree completely).
Goldin agrees, mostly as a favor to Sylvie's prominent husband, but then says that she didn't understand the film.
The behavior of s-PS/PVME agrees mostly with that of a-PS/PVME, indicating that tacticity or crystallinity in s-PS does not affect the phase behaviour of s-PS/PVME in the amorphous domain.
An Italian shoe company, he said, once paid someone $1,000 to track him down in New Mexico to see if he would do a fashion shoot, to which he agreed mostly because of the company's tenacity.
Not everyone agrees, mostly the vendors that are milking their cash cows.
"It means that the major providers of high-speed Internet access in the US, who have systematically divided markets and tacitly agreed mostly not to compete with one another, can treat high-speed Internet access like a cable TV service.
