Tant, tant de and tant que are common French forms expressing quantity, intensity, comparison, and conditions of time. They appear in both speech and writing across all registers.

Tant

Tant is an adverb meaning “so much,” “so,” or “so many,” depending on context. It often intensifies a verb or adjective.

With verbs

• Il travaille tant.
  He works so much.
• Tu parles tant que personne n’ose répondre.
  You talk so much that no one dares answer.
• Elle souffre tant qu’elle ne peut plus bouger.
  She suffers so much that she can no longer move.

With adjectives or adverbs

• C’est tant mieux.
  So much the better.
• C’est tant pis.
  Too bad.
• Il est tant soit peu intéressé.
  He is interested to some small degree.

Fixed expressions

• Tant mieux.
• Tant pis.
• Tant s’en faut. (far from it)
• Tant et si bien que… (to such an extent that)

Tant de

Tant de expresses a large quantity and means “so much,” “so many,” or “so much of.” It is followed by a noun without an article.

With countable nouns

• Il y a tant de livres ici.
  There are so many books here.
• J’ai rencontré tant de personnes sympathiques.
  I met so many nice people.
• Ils ont tant de problèmes.
  They have so many problems.

With uncountable nouns

• Tu mets tant de sucre dans ton café.
  You put so much sugar in your coffee.
• Elle a tant de courage.
  She has so much courage.
• Nous avons tant de travail aujourd’hui.
  We have so much work today.

Synonyms or alternatives

• Tellement de
• Autant de (same quantity)
• Beaucoup de (high quantity, neutral)

Tant que

Tant que functions mainly as a conjunction. It has several meanings: “as long as,” “while,” “so long as,” or “provided that,” depending on context.

1. Time: “as long as” or “while”

• Tant que tu restes ici, tu es en sécurité.
  As long as you stay here, you are safe.
• Tant que le soleil brille, continuons.
  As long as the sun is shining, let’s continue.
• Tant que je vivrai, je me souviendrai de toi.
  As long as I live, I will remember you.

Synonyms

• Aussi longtemps que
• Pendant que (when referring to simultaneous actions, not conditions)

2. Condition: “so long as” or “provided that”

• Tu peux venir tant que tu respectes les règles.
  You can come so long as you follow the rules.
• On peut sortir tant que la pluie s’arrête.
  We can go out provided the rain stops.
• Je t’aide tant que tu fais ta part.
  I will help you as long as you do your part.

Synonyms

• À condition que (requires the subjunctive)
• Pourvu que (requires the subjunctive)

3. Comparison of degree: “as much as”

• Tu peux manger tant que tu veux.
  You can eat as much as you want.
• Il peut dormir tant qu’il veut.
  He can sleep as much as he wants.
• Elle peut poser tant de questions qu’elle veut.
  She can ask as many questions as she wants.

Synonym

• Autant que

Confusion to avoid

Tant que must not be confused with tandis que, which means “whereas” and is used for contrasts.

Examples:

• Tant que tu es là, aide-moi.
  As long as you are here, help me.
• Tandis que tu travailles, je me repose.
  Whereas you work, I rest.

Summary

Tant intensifies a verb or adjective and can stand alone in fixed expressions. Tant de expresses a large quantity. Tant que introduces time, conditions, or comparisons. All are common, flexible forms used to talk about quantity, degree, and conditions in everyday French.