schmerzhaft
painful
Causing physical pain.
Die Injektion beim Arzt war kurz, aber schmerzhaft.
The injection at the doctor’s office was brief but painful.

painful
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painful
Causing physical pain.
Die Injektion beim Arzt war kurz, aber schmerzhaft.
The injection at the doctor’s office was brief but painful.

The adjective 'schmerzhaft' (painful) is formed from the noun 'der Schmerz' (pain) and the ending '-haft'. The ending '-haft' means 'having something' or 'causing something'. 'Schmerzhaft' (painful) therefore literally means 'causing pain'.
Das Ziehen des Zahns war weniger schmerzhaft als erwartet.
Having the tooth pulled was less painful than expected.
For emotional pain, 'schmerzhaft' (painful) is often combined with abstract nouns. Typical examples are 'eine schmerzhafte Erinnerung' (a painful memory), 'eine schmerzhafte Trennung' (a painful separation), or 'eine schmerzhafte Wahrheit' (a painful truth).
Die Trennung von seiner langjährigen Freundin war für ihn sehr schmerzhaft.
The separation from his longtime girlfriend was very painful for him.
In the figurative sense, 'schmerzhaft' (painful) is often used in economic or sports contexts to describe unpleasant losses or defeats. People then speak of 'schmerzhaften Verlusten' (painful losses) or 'einer schmerzhaften Niederlage' (a painful defeat).
Die Mannschaft musste eine schmerzhafte Niederlage im Finale hinnehmen.
The team had to suffer a painful defeat in the final.
sore / painful
'weh' and 'schmerzhaft' both have to do with pain. 'weh' is usually used in the expression 'weh tun' (to hurt): a body part hurts, or a remark hurts someone inside. 'schmerzhaft' is an adjective and describes a thing, experience, or treatment that causes pain. It sounds a bit more precise or factual. Learners confuse the words because both can express physical or emotional pain. As a simple guide: you say 'Mein Arm tut weh' (my arm hurts), but 'Die Behandlung ist schmerzhaft' (the treatment is painful).

Die Spritze war kurz schmerzhaft, aber danach ging es mir besser.
The injection was briefly painful, but afterward I felt better.
Nach dem Training tut mir der Rücken weh.
After training, my back hurts.