Je bois autant de café que de thé.

In French, when autant is followed by a noun, it must be autant de + noun.

• Correct: autant de café, autant de temps, autant de problèmes
• Incorrect: autant café, autant temps, etc.

So the pattern is:

autant de + noun + que + noun

Hence: autant de café que de thé.

There are actually two different de here, but they look the same:

1. de after autant:
   This is the de of quantity, used after expressions like:

   • autant de
   • beaucoup de
   • peu de
   • trop de

   So you must say: autant de café, never autant café.

2. de before thé after que:
   Here, de is repeated to keep the same structure:

   • autant de café que de thé = as much coffee as (I drink) tea.

Repeating de makes the comparison clear and balanced:

• autant de X que de Y

No, that sounds wrong in standard French.

After a quantity expression like autant de, you do not use du / de la / des. You keep de in its basic form:

• autant de café que de thé
• autant de vin que de bière
• autant de travail que de loisirs

So du is not used here because de is already required by the quantity expression.

In careful, standard French, you should keep the second de:

• Preferred: Je bois autant de café que de thé.

Without the second de, the sentence can sound incomplete or awkward, because que thé then looks like a direct object phrase rather than part of the comparison.

You might hear something like autant de café que thé in very informal speech, but for correct written and spoken French, use:

autant de [noun] que de [noun]

They both express equality, but they are used with different types of words.

1. With nouns (quantity), use autant de:

   • Je bois autant de café que de thé.
     I drink as much coffee as tea.
   • Il a autant d’amis que toi.
     He has as many friends as you.

2. With adjectives and adverbs, use aussi:

   • Ce café est aussi fort que ce thé.
     This coffee is as strong as this tea.
   • Je bois aussi rapidement que toi.
     I drink as quickly as you.

3. With verbs directly (not a noun), use autant que:

   • Je bois autant que toi.
     I drink as much as you (same amount, but the noun is implied).

So:

• autant de + noun + que
• aussi + adjective/adverb + que
• autant que + verb / subject

Grammatically, autant de café que de thé talks about quantity, not frequency.

• Most literal idea: similar amounts (liters, cups, etc.) of coffee and tea.

If you specifically want to talk about frequency (how often), French usually uses aussi souvent que:

• Je bois du café aussi souvent que du thé.
  I drink coffee as often as tea.

In real conversation, people might still understand it as “overall I drink as much coffee as tea (over time)”, but the structure itself is about quantity.

Autant de and tant de are different:

• autant de = as much / as many … as (comparison of equality)

  • J’ai autant de travail que toi.
    I have as much work as you.

• tant de = so much / so many (no comparison, just intensity)

  • Je bois tant de café.
    I drink so much coffee.

In your sentence, there is a comparison (as much coffee as tea), so you need autant de, not tant de.

No, that sounds unnatural or incorrect.

The structure autant de has to stay together, before the noun it qualifies:

• Je bois autant de café que de thé. ✅
• Je bois de café autant que de thé. ❌

Think of autant de as a single block that goes directly before the noun:

• autant de café
• autant de vin
• autant de livres

The structure itself does not change. You still use autant de:

• Je lis autant de livres que de magazines.
  I read as many books as magazines.

• Elle a autant de problèmes que de solutions.
  She has as many problems as solutions.

• Je bois autant de tasses de café que de tasses de thé.
  I drink as many cups of coffee as cups of tea.

So the pattern stays: > autant de + plural noun + que de + plural noun

In Je bois autant de café que de thé, a typical standard pronunciation is:

• Je bois autant de café que de thé
  /ʒə bwa otɑ̃ də kafe kə də te/

Details:

• autant → /otɑ̃/
  
  • final t is silent, -an is nasalized.
• No liaison between bois and autant in this case.
• de before consonants is usually /də/ in careful speech, often reduced in fast speech.

So you would hear something close to: > ʒə bwa otɑ̃ də kafe kə də te

They are very close in meaning, but:

• autant de café que de thé is the normal, idiomatic comparative form.
• la même quantité de café que de thé is more explicit and heavier, emphasizing the idea of “the same quantity”.

In everyday speech, people overwhelmingly use:

• Je bois autant de café que de thé.

You’d only say something like la même quantité de… if you really wanted to insist on the exact quantity, or in a more technical / formal context.