Indicative
Present Indefinite
I fasten upon
you fasten upon
he/she/it fastens upon
we fasten upon
you fasten upon
they fasten upon
Present Continuous
I am fastening upon
you are fastening upon
he/she/it is fastening upon
we are fastening upon
you are fastening upon
they are fastening upon
Present Perfect
I have fastened upon
you have fastened upon
he/she/it has fastened upon
we have fastened upon
you have fastened upon
they have fastened upon
Present Perfect Continuous
I have been fastening upon
you have been fastening upon
he/she/it has been fastening upon
we have been fastening upon
you have been fastening upon
they have been fastening upon
Past Indefinite
I fastened upon
you fastened upon
he/she/it fastened upon
we fastened upon
you fastened upon
they fastened upon
Past Continuous
I was fastening upon
you were fastening upon
he/she/it was fastening upon
we were fastening upon
you were fastening upon
they were fastening upon
Past Perfect
I had fastened upon
you had fastened upon
he/she/it had fastened upon
we had fastened upon
you had fastened upon
they had fastened upon
Past Perfect Continuous
I had been fastening upon
you had been fastening upon
he/she/it had been fastening upon
we had been fastening upon
you had been fastening upon
they had been fastening upon
Future Indefinite
I will fasten upon
you will fasten upon
he/she/it will fasten upon
we will fasten upon
you will fasten upon
they will fasten upon
Future Continuous
I will be fastening upon
you will be fastening upon
he/she/it will be fastening upon
we will be fastening upon
you will be fastening upon
they will be fastening upon
Future Perfect
I will have fastened upon
you will have fastened upon
he/she/it will have fastened upon
we will have fastened upon
you will have fastened upon
they will have fastened upon
Future Perfect Continuous
I will have been fastening upon
you will have been fastening upon
he/she/it will have been fastening upon
we will have been fastening upon
you will have been fastening upon
they will have been fastening upon
Conditional
Conditional Present
I would fasten upon
you would fasten upon
he/she/it would fasten upon
we would fasten upon
you would fasten upon
they would fasten upon
Conditional Present Continuous
I would be fastening upon
you would be fastening upon
he/she/it would be fastening upon
we would be fastening upon
you would be fastening upon
they would be fastening upon
Conditional Perfect
I would have fastened upon
you would have fastened upon
he/she/it would have fastened upon
we would have fastened upon
you would have fastened upon
they would have fastened upon
Conditional Perfect Continuous
I would have been fastening upon
you would have been fastening upon
he/she/it would have been fastening upon
we would have been fastening upon
you would have been fastening upon
they would have been fastening upon