Vi har massevis av tid.

Massevis means a lot, plenty, or loads. It is a fairly common informal word in Norwegian.

So Vi har massevis av tid means something like:

• We have plenty of time
• We have loads of time
• We have lots of time

It sounds natural and conversational.

In Norwegian, massevis is often followed by av before the noun:

• massevis av tid = plenty of time
• massevis av folk = lots of people
• massevis av penger = lots of money

This works a bit like English lots of or plenty of.
So av here means of.

Yes. Vi har mye tid is completely correct and means We have a lot of time.

The difference is mostly about style and emphasis:

• mye tid = a lot of time, neutral and common
• masse tid = lots of time, informal
• massevis av tid = loads/plenty of time, a bit more expressive

So all of these are natural, but massevis av tid feels especially abundant.

Because Norwegian uses ha (to have) in the same way English does here.

• Vi har tid = We have time

You are talking about possessing or having time available, not about being something.
So er would not work in this sentence.

Also, Norwegian verbs do not change by person the way they do in English:

• jeg har
• du har
• vi har

The form har stays the same.

Tid means time. In this sentence it is used as an uncountable noun, just like English time in We have plenty of time.

That is why there is no article:

• tid = time in general
• not en tid here

Using en tid would usually mean a time in a different sense, not the general uncountable idea.

It is mostly informal to neutral everyday language. It sounds very natural in conversation.

If you want something more neutral or slightly more formal, you might say:

• Vi har god tid = We have plenty of time / We are not in a hurry
• Vi har mye tid = We have a lot of time

But massevis av tid is not strange or wrong. It just feels a bit more lively and conversational.

This is a very useful distinction.

• massevis av tid focuses on quantity: there is a lot of time available
• god tid often means enough time, plenty of time, or no need to rush

Examples:

• Vi har massevis av tid = We have loads of time
• Vi har god tid = We have plenty of time / We are not pressed for time

In many situations they overlap, but god tid is especially common when talking about not being in a hurry.

Yes, very often. It is a productive expression.

Examples:

• massevis av penger = lots of money
• massevis av bøker = lots of books
• massevis av mennesker = lots of people
• massevis av problemer = lots of problems

So once you learn massevis av + noun, you can use it with many different nouns.

A simple learner-friendly approximation would be:

• Vi ≈ vee
• har ≈ haar
• massevis ≈ MAH-seh-vees
• av ≈ ahv
• tid ≈ teed

A few notes:

• vi usually has a long i sound
• tid also has a long i sound
• r in har depends on dialect
• in natural speech, massevis av may flow together smoothly

If you are learning standard Eastern Norwegian pronunciation, this approximation is close enough to get started.

Yes. The basic sentence is:

• Vi har massevis av tid.

But Norwegian often changes word order when another element comes first. For example:

• I dag har vi massevis av tid. = Today we have plenty of time.
• Nå har vi massevis av tid. = Now we have plenty of time.

Notice that when something like I dag or Nå comes first, the verb har comes before vi. This is because Norwegian follows the verb-second rule in main clauses.

They are very close, but not always identical in feel.

• masse tid = lots of time
• massevis av tid = loads/plenty of time

Masse is very common and informal.
Massevis often sounds a little more emphatic or a little fuller as an expression.

In everyday speech, both are natural.

Yes, absolutely. A native speaker might say it when reassuring someone not to rush:

• Slapp av, vi har massevis av tid. = Relax, we have plenty of time.

So it is a very usable, natural sentence for real conversation.