不通

to be obstructed / to be blocked up / to be impassable / to make no sense / to be illogical

no; not so / (bound form) not; un-

to go through / to know well / (suffix) expert / to connect / to communicate / open / to clear / classifier for letters, telegrams, phone calls etc

classifier for an activity, taken in its entirety (tirade of abuse, stint of music playing, bout of drinking etc)

won't work / will get (you) nowhere

lit. doesn't (even) enter a single aperture (of one's head) / I don't understand a word (idiom) / it's all Greek to me

this road is blocked / fig. This method does not work. / Doing this is no good.

lit. not one drop can trickle through (idiom); fig. impenetrable (crowd, traffic)

cannot get through (on phone)

unable to understand / unable to get over

it does not make sense

incoherent (writing or speech) / nonsensical / a load of crap

to not fully understand (idiom)

it does not make sense