Questions & Answers about Я несу тяжёлую корзину, и моя спина устала.
Why use несу instead of ношу in this sentence?
Несу is the unidirectional verb of motion for carrying something on foot. You use it here because the carrying is happening right now, in one specific direction. If you were talking about carrying a heavy basket every day, or carrying it back and forth, you would use the multidirectional verb ношу.
Why is it тяжёлую корзину instead of тяжёлая корзина?
The basket is the direct object of the verb несу (it is the thing being carried), so it needs to be in the accusative case. For feminine singular words, the adjective ending -ая changes to -ую (тяжёлую), and the noun ending -а changes to -у (корзину).
If I am carrying the basket right now, why is the verb устала (got tired) in the past tense?
In Russian, physical states like being tired are often expressed with the past tense of a perfective verb (a verb showing a completed action). Устала literally means the back has already gotten tired. The action of getting tired is complete, resulting in the current state of feeling tired right now.
Why does устала end in -а?
Past tense verbs in Russian must match the gender of the subject. The subject here is спина (back), which is a feminine noun, so the verb takes the feminine past tense ending -а.