signal
In German, 'Signal' is used in the same way as in English. It refers to a sign, a gesture, or a visual or auditory cue that conveys information or a command. It can also refer to a device or system that transmits or receives signals, such as a traffic light or a radio signal.
The signal is green.
In this context, 'Signal' is referring to a traffic light or another type of signaling device indicating a green or 'go' sentiment. It is a simple declarative sentence in the present tense.
We are waiting for a signal from him.
This sentence suggests that the speaker and others are awaiting some sort of indication or 'signal' from 'him'. This likely refers to a cue or sign to commence or stop a given action or event, or could be used metaphorically to represent waiting for a decision or confirmation.
I did not see the signal.
The speaker indicates that they failed to see or recognize the 'Signal'. This could refer to a literal missed sight of a physical sign or signal, or perhaps a metaphorical missed cue or hint. This sentence is in the past tense.