Answer :
To answer the question, you'll need to know when to use the '-ing' form of a verb and when to use 'to + infinitive'. Here's a step-by-step guide to the adjustments needed for each sentence:
Does this job need... (do) now or can I leave it until later?
- In this case, the correct form is 'doing' because certain verbs like 'need', when used in a passive sense, are often followed by an '-ing' form: "Does this job need doing now or can I leave it until later?"
I've got an extra bed, so when you come to stay, you won't need... your sleeping bag.
- Here, 'need' is followed by the base form without 'to' because it's used in a special sense: "...so when you come to stay, you won't need to bring your sleeping bag."
Tom helped his mother... (get) the dinner ready.
- With 'help', you can use either the base form or 'to + infinitive': "Tom helped his mother to get the dinner ready." or "Tom helped his mother get the dinner ready."
When he told me that everybody had made fun of him, I couldn't help... (feel) sorry for him.
- The expression 'can't help' is followed by an '-ing' form: "...I couldn't help feeling sorry for him."
Those shirts need... (iron) but you don't need...
- Similar to the first sentence, 'need' in the context of necessity follows with '-ing': "Those shirts need ironing but you don't need to iron them yourself."
He looks so funny. When I see him, I can't help... (smile).
- Again, 'can't help' is followed by an '-ing' form: "When I see him, I can't help smiling."
The fine weather helped... (make) it a very enjoyable holiday.
- With 'help', you typically use the base form or 'to + infinitive': "The fine weather helped to make it a very enjoyable holiday." or "The fine weather helped make it a very enjoyable holiday."
