Ⅰ.in time“及時(shí)”，指的是不遲到或在提前的時(shí)間之前做某事，后面可接不定式或for短語。
Ⅱ.on time“準(zhǔn)時(shí)”，指按規(guī)定的時(shí)間或指定的時(shí)間做某事，后面不可以跟不定式或for短語。如：
① Joe was just in time for the bud. Joe正好趕上那班汽車。
② They got there on time to see the exhibition. 他們準(zhǔn)時(shí)到那兒，去看了那個(gè)展覽。
③ Can you get there in time? 你能及時(shí)感到那兒?jiǎn)?
④ You must always return your library book on time. 你必須總是按時(shí)歸還從圖書館借的書。
Ⅱ.on time“準(zhǔn)時(shí)”，指按規(guī)定的時(shí)間或指定的時(shí)間做某事，后面不可以跟不定式或for短語。如：
① Joe was just in time for the bud. Joe正好趕上那班汽車。
② They got there on time to see the exhibition. 他們準(zhǔn)時(shí)到那兒，去看了那個(gè)展覽。
③ Can you get there in time? 你能及時(shí)感到那兒?jiǎn)?
④ You must always return your library book on time. 你必須總是按時(shí)歸還從圖書館借的書。