If you had nekudot, you would see under the tav of the vowel qamats, which in Sephardic Hebrew is usually pronounced "ah" just like a patakh. But in some words it is pronounced o because it is derived from a word that has a long o (best known is the word כל for "all" = kol, not kal); in this case, תכן tokhen, the verb for examine, measure, plan. Sorry I don't know how to do it on a smartphone, but picture a high dot between the tav and the khaf, and accent that first syllable. Segol under the khaf.
Please ask your friend if תַּלְמִיד is also commonly used for secular elementary-school students. I've been told by Israelis that סְטוּדֶנְט is commonly used for older students, such as post-high school.
You're asking if it is more natural for a native Hebrew speaker to use the word that sounds more like an English word. I do see many Hebrew loanwords from English, so maybe that is a trend, such as from cultural influence, rather than anything natural to Hebrew.
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