I am really confused in regards to how 是 is used in 好像／像 sentences and sometimes not used.
For example, I can come up with something like 那朵云好像是一朵棉花。 (that cloud looks like cotton.) Can I omit 是 here?
In another case, I can compose a sentence such as 我想像 David Beckham 踢得太好 (I want to play soccer as well as David Beckham) and 是 is not used here.
Can somebody help me understand usages of 好像／像 and how 是 is used and sometimes not used in those sentences?