Sarah
Every person has 'limits'.
A person's 'limit or limits' is the most or the best that they can do / the most that they can tolerate/endure.
e.g., I studied more than ever before. I really pushed my limits / I really pushed myself to my limit.
e.g., You have been bothering me all day. You're really pushing me to my limit (limit = the amount that I can handle and still be patient / pushing me to the point that I will lose my temper)
Every piece of equipment also has limits, the most/the fastest/ it can handle or at which it can operate safely.
e.g., The machine was designed to work safely/properly for 10 years. But we have been using it every day for 25 years. We are pushing the machine to its limit.
(limit = the most that the machine can do before it begins to stop working properly/begins to develop problems)
e.g., My car can drive fast, 140 kilometres per hour. Today I want to see if it can drive faster, so I will push it to its limit.
(limit = the highest speed that the car can drive at.)
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My favorite teacher WAS Mr. K, who pushed my limits when I was in school.
My favorite teacher was Mr. K., who encouraged me/forced me/pushed me to my limit
(limit = to do the best I could do / to do my best / to try even harder than before)