Use an asterisk * to represent any number of letters at the end of a word. For example, behav* will find behaviour, behavior, behave, behavioural, etc. This technique is called truncation.
In Web of Science you can also use the asterisk to represent any number of letters in the middle of a word, which can be useful for finding variations of spellings. For example, behavio*r will find behavior or behaviour .
Use a question mark ? to represent one letter in a word. For example, fertili?ation will find fertilisation and fertilization.
Use quotation marks to force a search for a phrase. For example, “cognitive behavioural therapy” will retrieve records that include those three words only in that exact order. This applies only to Topic and Title searches.
You can search for words that are used close to each other, without being in an exact phrase, by using the proximity operator NEAR/x. For example, deer NEAR/5 conservation will find "deer conservation", "conservation of deer", "conservation of red deer", etc. The /x element says how many other words will be allowed between the two keywords, in this case five - just using NEAR will be treated as NEAR/15. It doesn't matter what order the words are in.