Depuis où Pendant

Question 1

Depuis

Answer 1

A preposition of time
= since or for + an amount of time spent.
Used in the present tense.
Expresses condition that began in the past but are still in effect at the present time.
An equivalent expression in english would be in the past tense.
e.g Depuis quand est-il malade?
Since when has he been sick?

Question 2

Pendant

Answer 2

A preposition of time.
= during / for + an amount of time spent.
It indicates the COMPLETE DURATION of an event, which has no relation to the time at time of speaking.
It can be used with past, present and future tenses.
e.g Nous avons discuté pendant une heure.
We talked for an hour.

Question 3

À

Answer 3

Is a preposition of time
Is used to say what time something will happen.
E.g. Il va parler à midi.
He will speak at noon.

Question 4

Dans

Answer 4

Is a preposition of time.
It indicates the amount of time before something begins.
E.g Il va parler dans 20 minutes.
He will speak in 20 minutes.

Question 5

En

Answer 5

Is a preposition of time.
Expresses the length of time something will take or the month, season or year in which it takes place.
Il va parler en une heure.
He will speak for 1 hour.
Il va parler en hiver.
He will speak in winter.

Question 6

Pour

Answer 6

Can be a preposition of time.
Can only be used to talk about something in the future. If you are talking about the past you need to use pendant/durant.
E.g Il va parler pour 15 minutes.
He will speak for 15 minutes.