verb
to exert oneself, to tire
B1
Anstrengen means “to exert oneself” (sich anstrengen — to make an effort) and “to tire/strain” (to tire someone). It is separable, uses haben as auxiliary, has irregular participle angestrengt, and is reflexive for effort but sometimes non‑reflexive when tiring others in everyday use.
Examples
Diese Arbeit strengt mich sehr an.
This work is very tiring for me.
Die Sportler strengten sich an, obwohl das Wetter schlecht war.
The athletes exerted themselves even though the weather was bad.
Du hast dich sehr angestrengt.
You tried very hard.
Details
Mnemonics
Picture someone pushing a heavy cart and sweating — they are 'anstrengen' themselves.
Sounds like 'and-stretch-in' — imagine stretching and exerting yourself.
Notes
Often used reflexively (sich anstrengen) meaning 'to make an effort'. Non-reflexive use often means 'to strain' someone or 'to tire' someone. Past participle is 'angestrengt'.