The Use of Premasu Verb + Adjective


I just try to learn Japanese from a drama, however I get stuck in figuring
following sentence:

> 分かりやすすぎる

which more or less means:

> It is too easy to understand you.

I know 分かり comes from the verb 分かる which means "to understand (v)". And やすすぎる
which literally means too cheap. But I do not know how a premasu verb 分かり can
be an infinitive (to understand). Does every premasu verb on its own will
become an infinitive? Why don't use 分かること or 分かるの to make the verb to an
infinitive?

Thank you.

EDIT:

What I mean by an infinitive is a construction like below:

> to + plain verb

for example

> To read, To understand

However they are not used as a verb like below

> I want to read, I need time to understand you.




There are two common constructions you need to know to understand this.

Vmasu + やすい = easy to (verb)

Vmasu + にくい = hard to (verb)

So, for example, わかりにくい means “hard to understand.” And わかりやすい means “easy to
understand.”

These are い adjectives, so you can negate them, add すぎる, or whatever else you
do with an い adjective. Therefore, わかりやすすぎる means “too easy to understand.”

