1. Playing computer games in not good for your health. You may have some problems on your eyes.
(Do we have to use 'on' or 'in' before 'eyes'?)
2. The boy is planting a tree. He is adding some soil around the tree.
3. The boys are playing soccer in the mountain. One is kicking a ball. The other is trying to kick the ball
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Are the sentences all grammatical? Would you correct some errors? Thank you.
#1 - "in" or "with," not "on."
#2 is correct.
#3 - If the boys are IN the mountain, they would be in a cave or a tunnel. If they are outdoors, they are ON the mountain. A ball and THE ball are grammatically correct, but the two sentences are somewhat confusing. Are both boys playing with the same ball? Is one successful in kicking a ball and the other not so successful?
1. The correct preposition to use before 'eyes' is 'on'. Therefore, the sentence should be: Playing computer games is not good for your health. You may have some problems on your eyes.
2. The sentence is grammatically correct.
3. The corrected sentence would be: The boys are playing soccer in the mountains. One is kicking the ball while the other is trying to kick the ball.
Overall, the sentences are mostly grammatical with minor corrections made for clarity and proper preposition usage.