Question

I can't catch the train because I (be) late fill in the blank

Answer 1

Explanation:

I can’t catch the train because I will be late. “To be” or “be” is the most protean verb in English language and it is constantly changing in a discernible pattern. This is also treated as a slippery verb in English language and people use it so often which makes it irregular. here you need to use this verb "be" to complete the sentence.  

Answer 2

Explanation:

I can'nt catch the train because i will be late.