CzechCourse

if you say so; if you think so
Very common
phrase
Typemultiword
Subtypephrase
Structureconjunction + formal/plural finite verb
UsageResponding that you will accept what someone says, often with some hesitation.

Examples

If you say so.
Fine, if you say so.
I will go there, if you think so.
I will do it, if you think so.
Then yes, if you say so.