Distinguishing seit, seitdem and bis

Bis, Seit and Seitdem are very commonly used in sentences, especially in Nebensatz, but they have different usages that often cause confusion. Below is a guide on how to distinguish these 3 words along with detailed illustrative examples.

1. How to use bis (until)

Usage: bis is understood in the English sense as until, and is used to indicate an action or event that ends at some point in the future, or at least after the moment you are currently referring to.

Bis is used in Nebensatz.

VD1: Sie räumt auf, bis die Kinder aufwachen. (She tidies up until the children wake up.)

The sentence above uses bis to indicate that the action of the children waking up has not yet occurred, so her tidying up is an action currently taking place in the present.

VD2: Ich kann bis 4 Uhr morgens nicht schlafen. (I cannot fall asleep until 4 o'clock in the morning.)

We understand: before 4 in the morning I am not asleep, and by 4 in the morning or after 4 in the morning I have already fallen asleep.

1. How to use Seit and Seitdem (since / ever since)

Seit and Seitdem are commonly used to indicate and mark the starting point of something, describing an action that began in the past and continues up to the present.

2.1 Seit:

Seit + Dativ

Used with time references such as days, months, years, etc.

VD1: Seit letzter Woche ist ihre Familie umgezogen. (Her family has already moved away since last week.)

We understand: her family has moved away and since then they no longer live there.

VD2: Seit Januar 2022 hat Vinmart seinen Namen in Winmart geändert. (Since January 2022, Vinmart has changed its name to Winmart.)

We understand: from 1/2022 up to now, people no longer call it Vinmart but Winmart.VD3: Ich war seit 2 Stunden müde. (I had been tired for 2 hours already.)

We understand: I had been tired for the past 2 hours and now I still feel tired.

2.2 Seitdem:

Seitdem is a Konjunktion (Conjunction)

Seitdem is used in a Nebensatz.

VD1: Seitdem die Kinder zur Schule gegangen sind, ist es im Haus viel ruhiger geworden. (Since the children went to school, the house has become much quieter.)

Seitdem is used to mark the point in time from when the children went to school up to the present — since the children have not yet come home, the house has remained quiet.

VD2: Ich habe seitdem nichts mehr von ihm gehört. (I have not heard anything from him since then.)

In the example above there is only one clause; seitdem stands after the verb. We can see that Seitdem does not have to appear at the beginning of the sentence — it also depends on the context.