breathe
The German word 'atmen' is a verb that corresponds to the English word 'breathe'. It is used in the same way as its English counterpart, to describe the process of inhaling and exhaling air. For example, 'Ich atme tief ein und aus' translates to 'I breathe in and out deeply'.
I need to breathe
This is a simple sentence in present tense. The verb 'muss' (need to) is used here to express necessity and 'atmen' is basic form of the verb 'breathe' in English.
He cannot breathe
In this sentence, 'Er' is the third person singular pronoun that refers to 'He' in English. 'kann' is the conjugated form of the modal verb 'können' (can), and 'nicht' represents negation.
You should breathe deeply
This command uses 'Du' (you) with 'sollst', the second person singular present of 'sollen' (should). 'tief' (deeply) is an adverb acting upon 'atmen'.