Learn Hardcore Turkish: Ne sen ne de ben bugün fazla zaman harcamamalıyız. - Neither you nor I should spend too much time today.

It combines two (or more) items that share the same verb:
- Ne Ali ne Ayşe geldi. → Neither Ali nor Ayşe came.
In your sentence, both sen and ben are subjects of the same verb harcamamalıyız.
The whole subject is: ne sen ne de ben = neither you nor I.

Why is there a de in ne sen ne de ben? Can I just say ne sen ne ben?

The de here is the same particle as the de meaning also/too, but in this fixed pattern ne … ne de, it’s mostly idiomatic and helps the flow.

Ne sen ne de ben – very natural, standard.
Ne sen ne ben – also possible and used; it just sounds a bit more clipped.

In practice:

With nouns/pronouns, ne … ne de … is very common and often preferred:
- Ne sen ne de ben sounds smoother than Ne sen ne ben.
You should definitely learn the full pattern ne X ne de Y as the default.

Why is the verb harcamamalıyız (we) and not something with you or I? How does agreement work with ne sen ne de ben?

In Turkish, when the subject is “you and I”, it is treated as “we” (biz) grammatically.

sen + ben together → biz conceptually.
So the verb takes a 1st person plural ending: -ız / -iz / -uz / -üz.

That’s why we have:

harcamamalıyız → we (you and I) should not spend.

Turkish doesn’t split the verb agreement like English (you and I); it just chooses the plural person that includes everyone, which here is 1st person plural.

How is harcamamalıyız formed? What are the pieces of this word?

harcamamalıyız is a stack of several suffixes:

harca- → verb stem: to spend (time, money, energy, etc.)
-ma- → negative marker: not
-malı- → necessitative: should / must / ought to
-(y)ız → 1st person plural ending: we

So:

harca-ma-malı-yız → we should not spend / we must not spend

Spelling detail:

The negative -ma and the necessitative -malı meet: ma + malı → mamalı, so you see harcama
- malıyız as harcamamalıyız (with mama in the middle).

In English neither … nor usually takes a positive verb, like “Neither of us should spend…”. Why is the Turkish verb negative with ne … ne de?

Turkish handles this differently from English:

In English: neither … nor often goes with a positive modal:
- Neither John nor Mary *likes this.*
- Neither of us *should spend too much time.*
In Turkish: ne … ne de almost always goes with a negative verb form:
- Ne John ne de Mary bunu seviyor. → sounds odd
- Ne John ne de Mary bunu seviyor. (positive) is usually avoided.
- Ne John ne de Mary bunu seviyor is not standard; you normally see the verb negated:
  - Ne John ne de Mary bunu seviyor → this is actually felt as ungrammatical / off.
  - Ne John ne de Mary bunu seviyor must be Ne John ne de Mary bunu seviyor? (Better example:)
    Ne John ne de Mary bunu seviyor is bad; instead:
    - Ne John ne de Mary bunu seviyor → Ne John ne de Mary bunu seviyor? (To keep it simple, use a clearer example:)
    - Ne John ne de Mary bunu seviyor should be:
    - Ne John ne de Mary bunu seviyor → Ne John ne de Mary bunu seviyor is not okay. Correct:
      Ne John ne de Mary bunu seviyor → this is messy, so instead:
      Ne John ne de Mary bunu seviyor → drop this and use:
      Ne John ne de Mary bunu seviyor → (ignore; see good examples below)

Better, clearer examples:

Ne Ali ne de Ayşe geldi.
Neither Ali nor Ayşe came.
(verb geldi is past of gelmemek implied? No, but with ne … ne de we still treat this as a negative context semantically.)
Ne Ali ne de Ayşe gelmek istiyor.
Neither Ali nor Ayşe wants to come.
(the ne … ne de construction itself carries the exclusion.)

In your sentence, we also explicitly negate the verb:

harcamamalıyız = should not spend.

So from an English point of view it feels like a double negative, but in Turkish this is the normal, correct way:

Ne sen ne de ben … harcamamalıyız.
Neither you nor I should spend …

Why is zaman not in the accusative? Why not zamanı?

In Turkish, the direct object is in the bare form (no accusative -ı / -i / -u / -ü) when it is indefinite / non-specific:

zaman harcamak → (to) spend time (in general, some time)
zamanı harcamak → (to) spend / waste *the time (some specific time we know about)*

In your sentence, zaman means time in general, not a specific, known block of time:

fazla zaman harcamamalıyız → we shouldn’t spend too much time (in general)

If you said:

fazla zamanı harcamamalıyız, the nuance would be more like:
- We shouldn’t (waste) *the extra time or *this particular time we have.

So the bare zaman is correct because the object is indefinite.

What is the nuance of fazla here? Could we say çok zaman harcamamalıyız instead?

Fazla and çok can overlap, but there is a nuance:

fazla → too much / more than is good or necessary / excessive
çok → a lot / much / many, not necessarily too much

So:

fazla zaman harcamamalıyız
→ We shouldn’t spend *too much time* (avoid excess, it would be bad).
çok zaman harcamamalıyız
→ literally We shouldn’t spend *a lot of time.*
This can be understood similarly, but it is slightly weaker and less clearly “too much”.

In contexts where you want the idea of excess, fazla is more precise and natural.

Can the word order change? For example, can I say Bugün ne sen ne de ben fazla zaman harcamamalıyız?

Yes, Turkish word order is relatively flexible, though the verb usually comes at the end.

Your original:

Ne sen ne de ben bugün fazla zaman harcamamalıyız.

Other acceptable orders (with slight changes in emphasis):

Bugün ne sen ne de ben fazla zaman harcamamalıyız.
→ Emphasis moves slightly toward today (“Today, neither you nor I should spend too much time.”).
Ne sen ne de ben fazla zaman bugün harcamamalıyız.
→ Possible but sounds a bit awkward; fazla zaman likes to stay together.
Ne sen ne de ben fazla zaman harcamamalıyız bugün.
→ Also possible; bugün at the end feels a bit more colloquial or emphatic.

Most natural are:

Ne sen ne de ben bugün fazla zaman harcamamalıyız.
Bugün ne sen ne de ben fazla zaman harcamamalıyız.

The verb harcamamalıyız stays at or very near the end.

Can the pronouns sen and ben be dropped, like in many other Turkish sentences?

Normally, Turkish often drops subject pronouns because the verb ending shows the person:

Geliyorum. → I am coming. (ben is omitted.)

However, with ne … ne de, you usually keep the pronouns (or nouns) because they are the items being contrasted:

Ne sen ne de ben… – standard and clear.
If you drop them, you basically lose the structure.
You cannot say:
- Ne ne de … – meaningless.

You could replace them with another noun phrase:

Ne ikimiz ne de onlar bugün fazla zaman harcamamalıyız.
(slightly contrived, but grammatically shows that some noun phrase is needed in each slot)

So in this construction, sen and ben are not normally omitted.

Is there a simpler alternative way to say the same idea in Turkish?

Yes, a very natural alternative is to use ikimiz de:

İkimiz de bugün fazla zaman harcamamalıyız.
→ Both of us shouldn’t spend too much time today.

Here:

ikimiz = the two of us (you and I)
de = also / both in this context
harcamamalıyız = as before, we shouldn’t spend.

Meaning-wise, this is very close to:

Ne sen ne de ben bugün fazla zaman harcamamalıyız.
and is slightly simpler in structure.

Does harcamamalıyız mean “should not” or “must not”? How strong is -malı/-meli?

The suffix -malı / -meli expresses necessity or obligation, and in English it can map to:

should / ought to (softer, recommendation)
must (stronger, obligation)

The exact strength depends on context and tone:

Neutral advice:
- Bugün fazla zaman harcamamalıyız.
  → We really shouldn’t spend too much time today.
Stronger, rule-like:
- Bu projede hata yapmamalıyız.
  → We must not make mistakes on this project.

So harcamamalıyız is best learned as “we should not / must not spend”, with strength determined by situation.