Enough and adequate are both adjectives.
They are synonyms (words that mean the same thing).
So they both have the same meaning.
Enough is a simple word that is used often by everyone (a commonly used word).
Adequate is a higher level word that is used to say "enough" at a higher level or in a more professional or technical situation.
Enough means that the amount of something you have will satisfy a need or a want.
e.g. Everyone needs enough money to buy food.
e.g. I want to have enough education to get a good job.
Adequate means that something is good enough or the supply is enough to satisfy someone.
Adequate is usually followed by the preposition "to" or "for".
e.g. I have an adequate amount of food to last three days.
e.g. I do not need an expensive car. An average priced car is adequate for the driving that I need to do.
Adequate also means that something is good enough for some reason or purpose.
e.g. My Chinese speaking skills are not adequate to live alone in China, but you are from China so your spoken Chinese is definitely adequate to speak to everyone.
If I am speaking to friends, I will say "enough".
e.g. Do you have enough time to teach me Chinese?
If I am speaking to someone in a more formal situation (business people or professional people), I will use adequate.
e.g. I believe that my professional consulting skills are adequate to help your company improve it's safety and management procedures.
e.g. My new computer is adequate for the work that I have to do.
I hope I have given you enough examples.
And I hope my examples are adequate to explain the differences between these two words.
Yes, "adequate time" is a good expression, especially if you also explain why the amount of time is adequate (Do you really have an adequate amonut of time to learn several languages?).
Wow - long answer :)