DO NOT SAY I KNOW or I UNDERSTAND

#1. to be aware of
This means to know that something exists.
Ex. I'm aware of the lack of water in the office toilet.
Don't warry, an engineer is coming next Friday.

#2. to realize
to understand a situation.
sometimes suddenly.

Ex. I realise how frustrating it is that you pay checks were late this month but I couldn't sign them because I was on a yacht and the wife was terrible.

#3. to recognize
to accept that something is legal important or true.

Ex. I recognize how much it means to you to have natural light in the office but I have very sensitive eyes.

#4. to appreciate
to understand a situation and realize that it is important.

Ex. I appreciate why you'd like more sick pay but I'm afraid that people might abuse it.
sick pay...疾病手当

#5. to acknowledge
to accept or admit the existence or truth of something.

Ex. I acknowledge that the lack of toilet paper is frustrating but it's not hard to put a few sheets in your pocket each morning.

it's not hard~　それは難しいことじゃない。
each morning..毎朝

#6. to notice
to see or become conscious of something or someone.

Ex. I did notice that you have been parking by the entrance each day.
I understand that you have a bad leg but you must be considerate of more executive members of staff.

#7. I see
I understand - and that I'm paying attention to what someone is saying.

Ex. I was off sick yesterday because I had a stomach bug.
I see. Was there vomit? Because if there wasn't any vomit, you should've come in.
stomach bug...食あたり
off sick...病欠

#8. I see what you mean
further implying that you don't really agree.

Ex. I won't be able to finish that project tonight because it's my birthday and my husband is taking me out.
I see what you mean. I'll offer the project to somebody more dedicated.

#9. fair enough
used to show that you understand and accept what someone has said

Ex. I'm not coming to the office party on Friday night because I suffer from bad social anxiety.
Fair enough, see you on Monday , you loser.

further...さらに
implying...意味する
fair enough...(提案などに対して)けっこうだ,オーケーだ

#10. I see your point
#11. I take your point
#12. I don't blame you
#13. I get you
to get = to understand

#14. gotcha
Slang - I've understood you.